I hate pixel shit but somehow I rike this game.
The music is amazing; the smooth transitions to new screens is great. You need more sound effects for the smaller stuff though like unlocking doors, maybe footsteps, reading book UI sound fx, maybe a stairs stepping sound effect or something when you walk through transition doors?
Tutorial design is really good you introduce stuff better than me for sure. The setting of mount su-meru is really good I think you do even more with the story like death skeletons with notes left behind with more lore there is a ton you could do with it than just books laying around.
I wanted more to the gameplay like combat; but if you wanna have something that isn't too similar to zelda's combat consider a gun, or whip, idk some weapon that doesn't work like a sword and shield does and will still make the game unique puzzles alone wont be enough for the gameplay I dont want you to suffer like me and my puzzle platformer shit game as much as I enjoy puzzle only games and you might too its HARD to sell them to modern gamers and make a living.
if possible zooming /in/out the camera for bigger puzzle sections would be cool but I'm not sure if its possible with whatever engine this is made in.