Neat! Not much actual interesting gameplay here as it's just about wandering to world randomly finding the letters but chill vibes.
Looked nice with that chunky pixel art style. The main character differed a bit from the other styles as it didn't have that thick outline of all other objects. So the character weirdly is grouped more to background stuff like the small grass patches and flowers than main objects. Also the main text font meshed a bit with the overall style not being pixelated. There were some other texts (and the collectible letters) with more cohesive look in comparison to the rest of the game. The spinning animation on end too kinda was a stylistic mismatch as everything else was pixel perfect and when you straight up rotate pixel art sprites, it "breaks" the pixel grid. The main character also had this minor weird jittering in the walk animation or movement that made it look not that nice.
And now after reading the descriptions a bit more it's clear why there is a stylistic mismatch. It's because they are from different sources. 😅
So as I already mentioned, the gameplay aspect here was a tad bit too thin. There was no real way to be good at it. Just wandering out randomly. And for the hard mode, you'd just need to memorize everything. Doesn't sound like that much fun. The enemies and bombs (after triggering it once by accident) posed to threat at all. The enemies kinda weirdly also didn't give a crap about the laws of physics and were walking through objects and even on water.
This was pretty much the only real hurdle in the game. And not in a fun way either. Just felt unfair and needlessly precise with the huge hard to estimate collision shapes.
So the collision shapes being the full rect around the sprite (or even more sometimes) doesn't feel right. You should always try to visualize it from an isometric angle and have the collision shapes of objects be what the base of the object (what ever is near the ground level). That way it feel more "realistic" and can allow for going behind objects (or course need to then do proper z-ordering for the sprites to have them be drawn at the right levels). It'd be way easier to estimate where you can squeeze through and what gap is too tiny.
Anyways, good job! 👍