I'm playing it as I type this post...
Everything looks great up until the first dungeon. Some of your walls have tile errors along the topmost rows of bricks, near the corners.
Do you have issues on using scripts, or not? If not, I'd recommend using an NPC script to replace the dialog room where you're told to use bombs to get the key. If you would prefer a strictly vanilla design (vanilla, as in no scripts and only default features), you can use sensitive warps and identical screens to get a similar effect. Either method would help because having the dialog room in a high-traffic area can become a potential annoyance depending on how patient your player is.
Actually, there's a third method if you want to try something I haven't seen anybody do before. It's used to make fake cutscenes in SMW hacks. Make two sets of combos that fill out the alphabet. One set has each letter take up the left half of the tile, and the other uses the right half. Include periods and commas for basic punctuation. The letters should be done in white, and the rest should be transparent. Now, since you have a black area for text in the room already, rather than using the string editor, manually place your alphabet combos, alternating two layers and left/right alphabet combos to make a seamless font that fills in the space. Since you're using tiles, the text appears instantly and without a sound as well as not interrupting gameplay for an instant! (Let me know if my description didn't make sense, and I can try throwing together a reference for you, if needed.)
Difficulty feels nice, but maybe take away a couple fire shooters in the room with one in each corner as well as three Goriyas and a Bomb pickup. You seem to like fire shooters, but they can be difficult to dodge, and when you only have three Hearts, you don't have much room for error.
Outside of the first dungeon, you have a large mass of dead trees that stand out. I thought that you were supposed to use the Blue Candle to burn them down and make a shortcut, since they stand out very much against everything else, it's right next to the dungeon, and would demonstrate what to look for to find out what to use the Candle on. They didn't burn down. Either replace them with regular trees or it's probably a bug (which I suspect), and you should fix the trigger for that screen.
Okay, second dungeon now, and I'm seeing the same tile error again. I'm guessing that you have a walls-only screen that you copy/paste for building the general dungeon shapes, huh? (Speaking of dungeon shapes, I feel like you lied to me...)
Next tip: You know how the Bow and Arrow have to be found separately in order to fire Arrows? You can give the Arrow the graphics of both over each other, make the Bow itself an invisible tile, and have the player start with the Bow so that they only have to find the Arrow. Also, your hint for Level 2 is a bit misleading. I ended up pressing against every wall in the dungeon, convinced that I missed a walk-through wall into an unmarked room, searching for the Boss Key. You've already demonstrated that the game uses Boss Keys, so don't even bother bringing it up in the hint.
Armory has a pretty difficult boss considering you built it as a gauntlet, and if you die at the boss, you have to redo the entire dungeon again. Another "only if you're interested" thing, but if you use an FFC with Secret Flag 16 on it for the first room in a dungeon as well as a halfway point, set Secret Tile 16 to a Tile Warp, and make the first room in the dungeon use remote screen triggers so its secrets activate when the halfway room does, you can make perfectly-centered GB-style Miniboss warps without scripting. Linear dungeons like this one would benefit greatly with such a shortcut.
Did you put No Enemy Flags on the stone staircases in the desert so the "Leevers" can't climb up, and more importantly, can't submerge/emerge on them? That is a beautiful attention to detail! I love it!
It would be nice to have a warning that Potions don't stack BEFORE I wasted the money I could have saved for a Magic Shield...
Okay, I got to the entrance to Dungeon 3 before calling it quits for now. From what I've seen, I'm going to want to start money grinding for that Shield, and probably go back and finish the Armory since I'm assuming that I'm getting the Blue Ring from there.