I wrote down all of the puzzle solutions as I figured them out, so I figured I'd post this as a walkthrough.
Using SNES9X, the name-entry screen glitches, which is how my character got named "00000G". Save/Load seems to work, but starting from the mountain cave dumps you in an inescapable pit of spikes.
First item you get is the Mirror, and the route to the castle is filled with path-blocking tree stumps. The hole to enter the hidden path is in a different spot. There are only a couple of enemies before you get the sword and shield, which is a step up from Parallel Worlds, I suppose. The first dungeon is a relatively straightforward loop, where you get the Cape, use it to get the Big Key, and use that to unlock the big chest upstairs to get the Lamp. The Big Key also allows you to enter the basement, where you can find Zelda, and the Hammer is in the chest behind here. But when you return to the throne room, she announces the way is blocked and you need to find an outside route to the church. You can jump off one of the battlements to get back to where you originally snuck in. (Possible glitch: You can use the cap to get past the electric barrier--however, you can't go further due to crystal-switch blocks.) If you go through the first secret passage back into the castle, there's a second big chest with 100 rupees in it. Then you need to go through an overworld stump-and-peg maze to get to the church. (You don't get a full heart at the church, just a piece.)
The castle is filled with red soldiers (4 hits to kill), there are some annoyingly-placed spikes, there's a tiny strip of corridor over pits that you'll need to navigate through, and Zelda is guarded by TWO flail guards. Obviously, the difficulty is ramped up a bit.
Back in the overworld: The way east is blocked by heavy rocks. The way to Death Mountain is blocked by a crystal switch you need the boomerang for. There's a heart piece in the thieves den in Lost Woods. You need the Boots to reach the Master Sword.
In Kariko Village: Jump in the well and bomb the wall for a heart piece. Get the Bottle from the Inn and buy another one from the vendor. Get the Net from the sick kid. The Library contains a heart piece, but no book. The Maze south of town is unchanged and still has a heart piece. You need the glove to enter the haunted grove.
Overworld: You can get a heart piece in the cave with the wise man in the desert (though he gives you a clue about the Book being in the library, which appears to be a lie).
Going east from Hyrule Castle gets you to the Eastern Palace (there's a heart piece directly south of it), and the magic shop, but you need either boots or the glove to reach the waterfall. Sarahasla's house has a free recharge, but the sage is missing.
Eastern Palace: The spike-filled path to the left at the entrance leads to two heart pieces. The first small chest has the Mushroom. In general, when you see a crystal switch, you need to hit it (and there are several you need to bomb behind you as you leave rooms). The star on the floor marks a chest hidden by an overhang. The big chest holds a Blue Boomerang. The statues you'd normally kill with the bow die in one hit from the hammer, it's just harder to time. The boss is the Armos Knights, who are much harder without a bow. (They may have more hit points that usual, too.) They leave a heart container and the first pendant.
With the Mushroom, you can get the Magic Powder from the magic shop; and you can use that in the well next to the blacksmith to get the 1/2 magic upgrade.
Now you can take the path up to Death Mountain, a space-filling maze with boulders raining down on you and fake ladders leading up. There's a visible heart piece on spectacle rock, but no ark world portal to get to it. You can get to the turtle rock area, but there are no caves and the rock is blocked by heavy stones.
The Tower of Hera: (Bring green medicine; using the cape to cross spikes will drain you.) Climb the right stairs and fall through the hole in the left room to get to the chest, then mirror back to the entrance to reach the locked door. The basement has an annoying four-torches puzzle that seems to only give you bombs--it actually makes an invisible chest indicated by stars appear in the left staircase area, which contains the big key. You can use that in the upper area (after being creative with bombs and crystal switches) to reach the rest of the dungeon. There's a blue crystal block that's actually a pot (and can be smashed) in a row of pots. You need to manuver past the boss to jump into several holes to get to the big chest, which contains the Book of Mudora. Moldorm actually isn't too hard to beat, if you're patient you can hang out right past the spikes at lead to his arena and just hit him when he gets close. He drops a heart container and the second pendant.
Back down off the mountain, through the lost woods, through the village, around the lake, through the swamp, and through the desert, where you can use the Book to open the Desert Palace.
Desert Palace: In the top-left room, there's a key hidden behind the eye-statue. The left-top room leads to six chests, five of which you can't open by one of which holds a key. The lower-left room leads to a crystal switch (it's behind the torch) and an exit that leads to a heart piece, and there's a key on on to the pots on the way there. Once you hit the crystal switch, you can get to the row of torches to the left of the main area; the bottom one is a treasure chest (as indicated by the star). The top-middle room has a heart piece. The lower-right room (blocked by blue switch blocks) leads to the big key. When you have one small key and the big key, you need to leave and re-enter through the right-hand entry to reach the big chest, which holds the Power Glove. In the second part of the dungeon, smash the torch for a key (it's really a pot) and push the block under the star to open the door. Pound the statue with the hammer, then in the next room there's an invisible chest above the star. The tall torch in the next room hides the crystal switch (but one of the blue blocks is a fake again), and there's a key in the blocked off "torch" below it. The second big chest holds the Ice Rod. Light the four torches to move the wall. Lanmola's den now is smaller and has spikes in it.
At the entrance to the desert, there's a cave with a stone you can now lift to get the Flippers. You can then swim to the island in the middle of Lake Hylia, where there's a chest with the Shovel. Use the shovel to dig up the Flute in the haunted grove (it's in the upper-left under flowers), then play it in front of the weathercock to release the bird. You can go to the waterfall of wishing to get the Magic Boomerang and Magic Shield as usual, and there's a heart piece up where King Zora is normally.
Now you can go to the Chapel and push the mantle behind Zelda and the priest to do the underground passage in reverse; you need the glove to get the big key and the magic boomerang to hit a crystal switch and get access to the big chest, which holds the Pegasus Boots! You can also use the flute to fly to #7 to get the Bow from the watergate. Then head to the Lost Woods and claim the Master Sword. Stop by Sanctuary if you want, then head to the Castle Tower.
Castle Tower: In the first room, you need to lift a blue block, lift a fake spike to get a key, and flatten two blue blocks. In the second room, you can kill the second enemy when he gets close enough to the barrier to hit him with your sword. In the third room, you need to freeze a soldier with the ice rod and throw him at the crystal switch. On the second floor, there's a block you need to flatten and a key in one of the pots. Also, be careful of floor spikes. On the third floor, flatten the spikes and lift the floor, bomb the crystal switch to get it at the right orientation, then dash-bounce off the blue blocks to reach the chest with the big key. Then use the boomerang to switch the crystal back and pound empty space to form a bridge. Fourth floor, there's a invisible pot in the second room with a key. The third room is full of spaces to pound with the hammer, and the fourth requires lifting the floor. Fifth floor, pound empty space near the star to reach the big chest for the Moon Pearl. Sexth floor, the second big chest has a heart container. Then you fight four Aghanims (1 real, three clones, but no way to distinguish them except for who takes damage) in an arena full of spikes.
Then you're drawn into the Dark World for the very first time. Not that this matters, mind you, because the dark world dungeons appear to all be part of the Pyramid and you're sealed off from the rest of the place.
Blind's Dungeon (#4, left-most available door): Navigating the maze is pretty straightforward; there's a small chest with the third Bottle, a big key and a small key to find. The second section is the usual selection of disguised blocks (if in doubt, hammer things); when you go upstairs, after you bomb the sunroof, fall through the hole next to the star to continue on. Hit the crystal switch, get the key, then go to the basement. The first big chest is behind the girl in the prison, and contains the Hookshot. (The conveyor belt to get there and back is _really_ tricky.) You can use the hookshot to get the second big chest, which contains the Staff of Byrna...just in time for the battle with Blind on a field of floor spikes. If you're patient and good at dodging, you can wait until he comes to the lower part of the arena and wail on him there. He drops a heart container and the first crystal.
Watergate Dungeon (#2, second from left): You need the bow and hookshot to enter. Kill all of the red knights to make a chest with a key appear. Downstairs, bomb into the left-hand room; the knight conceals a star so you can get past the orange blocks. The right-hand room has a key you need the cape to reach. There's a bit of a maze that requires hitting crystal switches and moving in circles to get the big key; as long as you remember that you can hook off the orange and blue blocks, you'll be fine. The big chest has the Fire Rod. The big key door leads to a particularly annoying statue-pulling puzzle--as far as I could tell, it requires you to grab the statue from a skewed angle to get it through a space you shouldn't be able to. Above, the left room has a hidden big chest with the Ether Medallion, and the right room has an invisible staircase. Through the most obvious invisible door ever leads you to a third big chest with the Bombos Medallion and then to Kholdstare. You need to hit Kholdstare with the fire rod to break him out of the ice, but the ice is invisible. After that, the fight pretty much goes as normal. He drops a heart container and the second crystal.
Misery Mire (#6, third from left): You need to use Ether to freeze the bouncers (the ice rod doesn't work on them) so you can throw one at the switch to enter. In the next area, kill all the wizzrobes to open the door. The right-hand side of the next section will test your patience and timing, because you need to hook across, dash-bounce onto the platform, then switch to the cape and race to the top before the floor collapses, with no margin for error. That gets you a key. The top area also has a key (hammer a block, then push the one below it). Use the two keys to go left, light four torches to open the door, get the key from the fake torch in the middle of the spikes. Follow the path, hit the crystal switch, circle back through the land of too many wizzrobes, back to the central room. Here, circle through the top to get to the skull you couldn't reach before and hit the switch, then get the chest near the star in the lower-left. Now do the hellish hook, dash-bounce, cape combo again, but switch back to the hook after the fire-bar and snag the orange block to get to the big key. Now go back to the lower-left path off the main room, and go down to the room with two pits. You can hook across to that pound-block. Go upstairs to get a key. The go down, hook across some pits, and use the hammer to pound a path along the pit to the big chest while dodging eye-lasers. All this gets you the Cane of Somara. Go to the big key door (up near where you hit the crystal switch) and go downstairs. In the room with two rows of blocks, bomb up into the next room. Use the cane to make a block, throw it over the fence, then press Y again to make the block explode and hit the crystal switch. Before you go upstairs, go left, push one of the statues, and hit the crystal switch. Then go up, hook on the orange block, and go fight Vitreous. Now with more spikes! (He's also not too bad; just stay clear of the lightning.) He drops a heart container and the third crystal.
Palace of Darkness (#1, fourth from left): You need the cane of somara to create a block and throw it over the fence, the press Y to explode it and hit the crystal switch. You need to loop through the basement to get a small key; the basement also holds the first heart piece we've seen in a while. The path is fairly straight for a while and includes another heart piece, and you need to break a wall south of one of the teleporters. Bomb both cracked walls and the left room holds a third heart piece. The dungeon looks more complicated than it is, but it's mostly just flipping crystal switches when you see them, getting keys and opening the only available doors, and bombing cracked walls. Remember to get an extra small key by pounding across the empty space by the star in the main room. (If you get stuck at a switch with nothing to hold it down, remember that you have the cane of somara now.) The big chest has the Titan's Mitt. In the room with ten statues, you need to shoot one in the eye with an arrow (top row, second from the left). The Helmasaur King now lives in a room full of conveyor belts to make him extra-painful. He drops a heart container and the fourth crystal.
You can now lift the heavy stone and get to the other three dungeons, and the heart piece on the side of the pyramid.
Dark Woods (#3, fifth from left): In the first room, the middle lamp is a chest with a key. The second room has an invisible wall at the bottom. Grab keys, use the cape to get by bumpers, remember that you cacn hook the switch blocks. (Gibdos hit hard, but you can use the fire rod on them. Wallmasters are just super-annoying.) In the room with the crystal switch, the best solution I found was firing an arrow over the blue blocks and then running up the side after it so it hits the switch. (To turn it back off, just drop a bomb and cross the blocks before it goes off.) Three small keys will get you the big key; then drop a cane of somara block on the switch and follow the path around to the big chest, which contains the Mirror Shield. In the next room, the big skull block is a fake you can hook past; in the room after that, you can pound the big skull block to continue. Get the room set up, then light all four torchs to open the door. Cut the vines in the north to reveal a door. Kill the gibdos for a small key. Jump in the hole to fight Mothula, who already had a moving floor and spikes, so he's basically unchanged from originally. He drops a heart container and crystal, as usual.
Ice Cavern (#5, sixth from left): Remember that the hookshot kills the sliding pengators in one hit. Again, the dungeon is pretty linear and nothing you haven't seen before, just annoyingly covered in ice floors. The fourth Bottle is on the main path. Get keys, hit switches, be careful, nothing surprising. The boss is Kholdstare and the invisible ice again, only now with 2/3rds of the arena covered in floor spikes. He drops a heart container and crystal, as usual. You need to re-enter and re-do a chunk of the dungeon to reach the big chest, which contains the Tempered Sword.
If the seventh dungeon opens with a diagonal wall and unreachable door, and no "?" point for a cane of somoara platform, then you've got the wrong ROM. Find "Legend of Zelda, The - A Link to the Past (U) [!].smc" and repatch. (You can just rename your save file--no need to relpay the game.)
Turtle Rock (#7, seventh from left): Use the cane of somara to make a platform, then hook to the door. Remember that the cane-platforms move the direct you're facing at crossroads. (There are a lot of walls that'll knock you off in here.) Lower-left door, use the cape to cross the spikes for a small key, and crab-walk (charge your sword) while facing down to exit the room. The right-top room is a light four torchs puzzle that involves a lot of hook-shoting and many annoying holes (start at the bottom). Dodge the spikes above for a second small key. Top-right room, dodge the floor tiles, then push the block in the next room for a third small key. Top-left room, use your three keys to continue. Most of the puzzles on the second floor are pretty straightforward--kill hoppers (you can use a medallion to take out a room full of them easily), find keys, flip the crystal switch, pull the tongue on one of the statues with pound-blocks in front of them. Dodge a lot. Pound across the hole in the room south of the big chest, then lift the block for a small key. The room with the big chest requires you to put a playform on the left "?", then hook right, then hook onto the platform. The chest has the Blue Mail. Use two small keys to get downstairs, then grab another one from the four skulls. Pound your way through the block maze to the second big chest, which holds the Quake Medallion. Get past the annoying platform maze (lot of dead-ends, here) to fight Trinexx, with more spikes added to his arena. He drops a heart container and the final crystal.
Back in the light world, you can go up to eastern Death Mountain and pound the three stakes (right, top, left) to reveal a warp point. This allows you to reach Ganon's Tower and the piece of heart on spectacle rock.
Ganon's Tower: Pound the Ganon statue on the far right to go downstairs. In the basement, lift everything looking for keys, remember that you can hit switchs with somara blocks, and remember the different things you can hook onto. The path is linear, includes two heart pieces, and leads to the big key and big chest containing the Red Mail. The trip upstairs is mostly a gauntlet of enemies and spikes, though you'll need to pound another Ganon statue and one room room has two statues in the middle that are actually the second big chest, containing the Golden Sword. In the "light four torches" room, you need to creep diagonally between the holes to remove the skull and light the top torch. On the next floor, you need to switch the crystal back (so that blue is up) after lighting the torches but before leaving the room (use the boomerang). Then lay a bomb and throw it onto the conveyor belt. This Moldorm is really easy, because you can strike him through the walls and he only takes two hits with the gold sword. Then comes the spikes-and-ice hell, and two big chests: The one behind blue blocks is the Silver Arrows. There's a hidden crystal switch in the left-most torch; the second big chest holds the final heart container. Then comes an anti-climatic battle with Aghanim, which seems easier than the previous one.
Ganon seems a bit faster than usual, but otherwise the battle is how you'd expect it. Congratulations!
Using SNES9X, the name-entry screen glitches, which is how my character got named "00000G". Save/Load seems to work, but starting from the mountain cave dumps you in an inescapable pit of spikes.
First item you get is the Mirror, and the route to the castle is filled with path-blocking tree stumps. The hole to enter the hidden path is in a different spot. There are only a couple of enemies before you get the sword and shield, which is a step up from Parallel Worlds, I suppose. The first dungeon is a relatively straightforward loop, where you get the Cape, use it to get the Big Key, and use that to unlock the big chest upstairs to get the Lamp. The Big Key also allows you to enter the basement, where you can find Zelda, and the Hammer is in the chest behind here. But when you return to the throne room, she announces the way is blocked and you need to find an outside route to the church. You can jump off one of the battlements to get back to where you originally snuck in. (Possible glitch: You can use the cap to get past the electric barrier--however, you can't go further due to crystal-switch blocks.) If you go through the first secret passage back into the castle, there's a second big chest with 100 rupees in it. Then you need to go through an overworld stump-and-peg maze to get to the church. (You don't get a full heart at the church, just a piece.)
The castle is filled with red soldiers (4 hits to kill), there are some annoyingly-placed spikes, there's a tiny strip of corridor over pits that you'll need to navigate through, and Zelda is guarded by TWO flail guards. Obviously, the difficulty is ramped up a bit.
Back in the overworld: The way east is blocked by heavy rocks. The way to Death Mountain is blocked by a crystal switch you need the boomerang for. There's a heart piece in the thieves den in Lost Woods. You need the Boots to reach the Master Sword.
In Kariko Village: Jump in the well and bomb the wall for a heart piece. Get the Bottle from the Inn and buy another one from the vendor. Get the Net from the sick kid. The Library contains a heart piece, but no book. The Maze south of town is unchanged and still has a heart piece. You need the glove to enter the haunted grove.
Overworld: You can get a heart piece in the cave with the wise man in the desert (though he gives you a clue about the Book being in the library, which appears to be a lie).
Going east from Hyrule Castle gets you to the Eastern Palace (there's a heart piece directly south of it), and the magic shop, but you need either boots or the glove to reach the waterfall. Sarahasla's house has a free recharge, but the sage is missing.
Eastern Palace: The spike-filled path to the left at the entrance leads to two heart pieces. The first small chest has the Mushroom. In general, when you see a crystal switch, you need to hit it (and there are several you need to bomb behind you as you leave rooms). The star on the floor marks a chest hidden by an overhang. The big chest holds a Blue Boomerang. The statues you'd normally kill with the bow die in one hit from the hammer, it's just harder to time. The boss is the Armos Knights, who are much harder without a bow. (They may have more hit points that usual, too.) They leave a heart container and the first pendant.
With the Mushroom, you can get the Magic Powder from the magic shop; and you can use that in the well next to the blacksmith to get the 1/2 magic upgrade.
Now you can take the path up to Death Mountain, a space-filling maze with boulders raining down on you and fake ladders leading up. There's a visible heart piece on spectacle rock, but no ark world portal to get to it. You can get to the turtle rock area, but there are no caves and the rock is blocked by heavy stones.
The Tower of Hera: (Bring green medicine; using the cape to cross spikes will drain you.) Climb the right stairs and fall through the hole in the left room to get to the chest, then mirror back to the entrance to reach the locked door. The basement has an annoying four-torches puzzle that seems to only give you bombs--it actually makes an invisible chest indicated by stars appear in the left staircase area, which contains the big key. You can use that in the upper area (after being creative with bombs and crystal switches) to reach the rest of the dungeon. There's a blue crystal block that's actually a pot (and can be smashed) in a row of pots. You need to manuver past the boss to jump into several holes to get to the big chest, which contains the Book of Mudora. Moldorm actually isn't too hard to beat, if you're patient you can hang out right past the spikes at lead to his arena and just hit him when he gets close. He drops a heart container and the second pendant.
Back down off the mountain, through the lost woods, through the village, around the lake, through the swamp, and through the desert, where you can use the Book to open the Desert Palace.
Desert Palace: In the top-left room, there's a key hidden behind the eye-statue. The left-top room leads to six chests, five of which you can't open by one of which holds a key. The lower-left room leads to a crystal switch (it's behind the torch) and an exit that leads to a heart piece, and there's a key on on to the pots on the way there. Once you hit the crystal switch, you can get to the row of torches to the left of the main area; the bottom one is a treasure chest (as indicated by the star). The top-middle room has a heart piece. The lower-right room (blocked by blue switch blocks) leads to the big key. When you have one small key and the big key, you need to leave and re-enter through the right-hand entry to reach the big chest, which holds the Power Glove. In the second part of the dungeon, smash the torch for a key (it's really a pot) and push the block under the star to open the door. Pound the statue with the hammer, then in the next room there's an invisible chest above the star. The tall torch in the next room hides the crystal switch (but one of the blue blocks is a fake again), and there's a key in the blocked off "torch" below it. The second big chest holds the Ice Rod. Light the four torches to move the wall. Lanmola's den now is smaller and has spikes in it.
At the entrance to the desert, there's a cave with a stone you can now lift to get the Flippers. You can then swim to the island in the middle of Lake Hylia, where there's a chest with the Shovel. Use the shovel to dig up the Flute in the haunted grove (it's in the upper-left under flowers), then play it in front of the weathercock to release the bird. You can go to the waterfall of wishing to get the Magic Boomerang and Magic Shield as usual, and there's a heart piece up where King Zora is normally.
Now you can go to the Chapel and push the mantle behind Zelda and the priest to do the underground passage in reverse; you need the glove to get the big key and the magic boomerang to hit a crystal switch and get access to the big chest, which holds the Pegasus Boots! You can also use the flute to fly to #7 to get the Bow from the watergate. Then head to the Lost Woods and claim the Master Sword. Stop by Sanctuary if you want, then head to the Castle Tower.
Castle Tower: In the first room, you need to lift a blue block, lift a fake spike to get a key, and flatten two blue blocks. In the second room, you can kill the second enemy when he gets close enough to the barrier to hit him with your sword. In the third room, you need to freeze a soldier with the ice rod and throw him at the crystal switch. On the second floor, there's a block you need to flatten and a key in one of the pots. Also, be careful of floor spikes. On the third floor, flatten the spikes and lift the floor, bomb the crystal switch to get it at the right orientation, then dash-bounce off the blue blocks to reach the chest with the big key. Then use the boomerang to switch the crystal back and pound empty space to form a bridge. Fourth floor, there's a invisible pot in the second room with a key. The third room is full of spaces to pound with the hammer, and the fourth requires lifting the floor. Fifth floor, pound empty space near the star to reach the big chest for the Moon Pearl. Sexth floor, the second big chest has a heart container. Then you fight four Aghanims (1 real, three clones, but no way to distinguish them except for who takes damage) in an arena full of spikes.
Then you're drawn into the Dark World for the very first time. Not that this matters, mind you, because the dark world dungeons appear to all be part of the Pyramid and you're sealed off from the rest of the place.
Blind's Dungeon (#4, left-most available door): Navigating the maze is pretty straightforward; there's a small chest with the third Bottle, a big key and a small key to find. The second section is the usual selection of disguised blocks (if in doubt, hammer things); when you go upstairs, after you bomb the sunroof, fall through the hole next to the star to continue on. Hit the crystal switch, get the key, then go to the basement. The first big chest is behind the girl in the prison, and contains the Hookshot. (The conveyor belt to get there and back is _really_ tricky.) You can use the hookshot to get the second big chest, which contains the Staff of Byrna...just in time for the battle with Blind on a field of floor spikes. If you're patient and good at dodging, you can wait until he comes to the lower part of the arena and wail on him there. He drops a heart container and the first crystal.
Watergate Dungeon (#2, second from left): You need the bow and hookshot to enter. Kill all of the red knights to make a chest with a key appear. Downstairs, bomb into the left-hand room; the knight conceals a star so you can get past the orange blocks. The right-hand room has a key you need the cape to reach. There's a bit of a maze that requires hitting crystal switches and moving in circles to get the big key; as long as you remember that you can hook off the orange and blue blocks, you'll be fine. The big chest has the Fire Rod. The big key door leads to a particularly annoying statue-pulling puzzle--as far as I could tell, it requires you to grab the statue from a skewed angle to get it through a space you shouldn't be able to. Above, the left room has a hidden big chest with the Ether Medallion, and the right room has an invisible staircase. Through the most obvious invisible door ever leads you to a third big chest with the Bombos Medallion and then to Kholdstare. You need to hit Kholdstare with the fire rod to break him out of the ice, but the ice is invisible. After that, the fight pretty much goes as normal. He drops a heart container and the second crystal.
Misery Mire (#6, third from left): You need to use Ether to freeze the bouncers (the ice rod doesn't work on them) so you can throw one at the switch to enter. In the next area, kill all the wizzrobes to open the door. The right-hand side of the next section will test your patience and timing, because you need to hook across, dash-bounce onto the platform, then switch to the cape and race to the top before the floor collapses, with no margin for error. That gets you a key. The top area also has a key (hammer a block, then push the one below it). Use the two keys to go left, light four torches to open the door, get the key from the fake torch in the middle of the spikes. Follow the path, hit the crystal switch, circle back through the land of too many wizzrobes, back to the central room. Here, circle through the top to get to the skull you couldn't reach before and hit the switch, then get the chest near the star in the lower-left. Now do the hellish hook, dash-bounce, cape combo again, but switch back to the hook after the fire-bar and snag the orange block to get to the big key. Now go back to the lower-left path off the main room, and go down to the room with two pits. You can hook across to that pound-block. Go upstairs to get a key. The go down, hook across some pits, and use the hammer to pound a path along the pit to the big chest while dodging eye-lasers. All this gets you the Cane of Somara. Go to the big key door (up near where you hit the crystal switch) and go downstairs. In the room with two rows of blocks, bomb up into the next room. Use the cane to make a block, throw it over the fence, then press Y again to make the block explode and hit the crystal switch. Before you go upstairs, go left, push one of the statues, and hit the crystal switch. Then go up, hook on the orange block, and go fight Vitreous. Now with more spikes! (He's also not too bad; just stay clear of the lightning.) He drops a heart container and the third crystal.
Palace of Darkness (#1, fourth from left): You need the cane of somara to create a block and throw it over the fence, the press Y to explode it and hit the crystal switch. You need to loop through the basement to get a small key; the basement also holds the first heart piece we've seen in a while. The path is fairly straight for a while and includes another heart piece, and you need to break a wall south of one of the teleporters. Bomb both cracked walls and the left room holds a third heart piece. The dungeon looks more complicated than it is, but it's mostly just flipping crystal switches when you see them, getting keys and opening the only available doors, and bombing cracked walls. Remember to get an extra small key by pounding across the empty space by the star in the main room. (If you get stuck at a switch with nothing to hold it down, remember that you have the cane of somara now.) The big chest has the Titan's Mitt. In the room with ten statues, you need to shoot one in the eye with an arrow (top row, second from the left). The Helmasaur King now lives in a room full of conveyor belts to make him extra-painful. He drops a heart container and the fourth crystal.
You can now lift the heavy stone and get to the other three dungeons, and the heart piece on the side of the pyramid.
Dark Woods (#3, fifth from left): In the first room, the middle lamp is a chest with a key. The second room has an invisible wall at the bottom. Grab keys, use the cape to get by bumpers, remember that you cacn hook the switch blocks. (Gibdos hit hard, but you can use the fire rod on them. Wallmasters are just super-annoying.) In the room with the crystal switch, the best solution I found was firing an arrow over the blue blocks and then running up the side after it so it hits the switch. (To turn it back off, just drop a bomb and cross the blocks before it goes off.) Three small keys will get you the big key; then drop a cane of somara block on the switch and follow the path around to the big chest, which contains the Mirror Shield. In the next room, the big skull block is a fake you can hook past; in the room after that, you can pound the big skull block to continue. Get the room set up, then light all four torchs to open the door. Cut the vines in the north to reveal a door. Kill the gibdos for a small key. Jump in the hole to fight Mothula, who already had a moving floor and spikes, so he's basically unchanged from originally. He drops a heart container and crystal, as usual.
Ice Cavern (#5, sixth from left): Remember that the hookshot kills the sliding pengators in one hit. Again, the dungeon is pretty linear and nothing you haven't seen before, just annoyingly covered in ice floors. The fourth Bottle is on the main path. Get keys, hit switches, be careful, nothing surprising. The boss is Kholdstare and the invisible ice again, only now with 2/3rds of the arena covered in floor spikes. He drops a heart container and crystal, as usual. You need to re-enter and re-do a chunk of the dungeon to reach the big chest, which contains the Tempered Sword.
If the seventh dungeon opens with a diagonal wall and unreachable door, and no "?" point for a cane of somoara platform, then you've got the wrong ROM. Find "Legend of Zelda, The - A Link to the Past (U) [!].smc" and repatch. (You can just rename your save file--no need to relpay the game.)
Turtle Rock (#7, seventh from left): Use the cane of somara to make a platform, then hook to the door. Remember that the cane-platforms move the direct you're facing at crossroads. (There are a lot of walls that'll knock you off in here.) Lower-left door, use the cape to cross the spikes for a small key, and crab-walk (charge your sword) while facing down to exit the room. The right-top room is a light four torchs puzzle that involves a lot of hook-shoting and many annoying holes (start at the bottom). Dodge the spikes above for a second small key. Top-right room, dodge the floor tiles, then push the block in the next room for a third small key. Top-left room, use your three keys to continue. Most of the puzzles on the second floor are pretty straightforward--kill hoppers (you can use a medallion to take out a room full of them easily), find keys, flip the crystal switch, pull the tongue on one of the statues with pound-blocks in front of them. Dodge a lot. Pound across the hole in the room south of the big chest, then lift the block for a small key. The room with the big chest requires you to put a playform on the left "?", then hook right, then hook onto the platform. The chest has the Blue Mail. Use two small keys to get downstairs, then grab another one from the four skulls. Pound your way through the block maze to the second big chest, which holds the Quake Medallion. Get past the annoying platform maze (lot of dead-ends, here) to fight Trinexx, with more spikes added to his arena. He drops a heart container and the final crystal.
Back in the light world, you can go up to eastern Death Mountain and pound the three stakes (right, top, left) to reveal a warp point. This allows you to reach Ganon's Tower and the piece of heart on spectacle rock.
Ganon's Tower: Pound the Ganon statue on the far right to go downstairs. In the basement, lift everything looking for keys, remember that you can hit switchs with somara blocks, and remember the different things you can hook onto. The path is linear, includes two heart pieces, and leads to the big key and big chest containing the Red Mail. The trip upstairs is mostly a gauntlet of enemies and spikes, though you'll need to pound another Ganon statue and one room room has two statues in the middle that are actually the second big chest, containing the Golden Sword. In the "light four torches" room, you need to creep diagonally between the holes to remove the skull and light the top torch. On the next floor, you need to switch the crystal back (so that blue is up) after lighting the torches but before leaving the room (use the boomerang). Then lay a bomb and throw it onto the conveyor belt. This Moldorm is really easy, because you can strike him through the walls and he only takes two hits with the gold sword. Then comes the spikes-and-ice hell, and two big chests: The one behind blue blocks is the Silver Arrows. There's a hidden crystal switch in the left-most torch; the second big chest holds the final heart container. Then comes an anti-climatic battle with Aghanim, which seems easier than the previous one.
Ganon seems a bit faster than usual, but otherwise the battle is how you'd expect it. Congratulations!