Select Normal or Hero mode when creating a save file like in the Switch remake - Hero Mode has a mirrored world, you take double the damage and deal half the damage, and hearts don't drop
Subscreen overhaul
The subscreen (pause screen) now scrolls up like in the original
The subscreen has been split like in Oracle of Ages, to avoid overcrowding like in DX (press Select to switch subscreens)
You can now create item presets to avoid switching items so often (create presets on the subscreen, switch during gameplay with Select+A/B)
Save and quit from the subscreen (no more A+B+Start+Select)
The dungeon map has been moved to the regular map screen
The boomerang now has a permanent item slot like in the Switch remake (you don't have to trade away anything)
The power bracelet is now a permanent item like in the Switch remake (press A in front of something to lift it)
Unequip the red/blue tunic
The ocarina song selection now pops up when equipping the ocarina, not when merely selecting it
Item colors are more consistent
Sprites no longer appear on top of the "status line" during gameplay
Map
The map no longer has a grid
The map uses more colors and a more varied tileset
The map screen (Select) now displays the dungeon map when in a dungeon
The map screen rolls up with a cool effect
Misc
The player name no longer has spaces after it if it's shorter than 5 characters
Crystal blocks/switches in dungeons are now orange and blue like in the Switch remake
Key Cavern has been renamed Key Cellar, to fit better with its nature and the original Japanese name
The shopkeeper will no longer deal vigilante justice simply for suspecting you of theft, he needs proof by catching you again (stealing for the first time now has no consequences, but you can only do it once)
The shopkeeper now closes the door behind you when he wants to punish you (based on a feature early in the game's development)
Bug fixes
This version also fixes a number of bugs in the original game.
Link can no longer change his tunic by killing 90 enemies in a row in the overworld
Dialog boxes will no longer have an empty line at the end if the dialog consists of an odd number of lines where the last line is 16 characters long
Cliff faces that Link can jump down now have the correct tiles
The copy/erase screens now have symmetric dividing lines
The cactuses (cacti?) in Yarna Desert now have more natural colors
Tale Keyhole has been renamed Tail Keyhole
The book on top of the library bookcase no longer weighs more than the Power Bracelet can carry (in fact, Link can no longer pick it up at all) and it's no longer made of the most impervious material known to man (projectiles now pass over it)
The game has slightly less green in it:
The Bird Keyhole rock now looks more like the DX rocks, and isn't green anymore
The staircase leading into Eagle's Tower is no longer half green the first time it's revealed
The Dodongo Snakes are no longer green until they turn for the first time