Scatterbrained feedback:
A master option for the volume would be nice.
Can't click the slide bar in the hotkey menu and the list doesn't scroll properly when I use the arrow key to navigate it.
Enemies get stuck on chests and traps, they have trouble navigating around the library room.
^doomcaller stuck on traps
Items stay on the hot bar even after using them all. Is there a way to rearrange them?
Enemy status effect should show up on their health bar
Fire shield description says "lasts _ seconds"
I killed the boss, did a couple of floors and then got bored so I started running past enemies, I think that part is endless?
I don't like melee combat in this game. The power bar is glacial and it takes too long to reach the red part so it throws away your timing.
Also it's hard to gauge weapon reach by eye and holding S plus sprint while timing a strike over and over is not that fun.
Could use some dodge/stun/block/push mechanics to be more interesting.
I picked up a fire book from the initial chest and never used anything else. Mana replenishing automatically means that it's viable to use as your only weapon.
My suggestion would be to balance around (an improved version of) melee combat and leave the spells as buffs/debuffs or a limited pool otherwise everyone is going to use nothing but spells considering that they're so much safer and more effective.
The dungeon itself gets boring quickly, the only cool thing that happened was finding a secret in a library but even that gave me like 10 apples and nothing else.
Visuals are not great, not talking about the enemy sprites but the dungeon itself: it's so blurry, repetitive and evenly lit, it's an eye sore.
I think you should re-evaluate the core melee combat mechanic and find ways to make dungeon rooms more exciting. I don't mind the billboarding sprite but I think they're only justified if you have a ton of enemies, people will expect either 3D models or more detailed and properly lit sprites.