Please make the camera follow the mouse, not the other way around. Camera turning left when going right doesn't feel good especially after years of muscle memory on practically every game having the camera controlled the same way. Still on the issue of the camera, you cannot zoom out so you have to re-enter the windmill to reset the zoom level on the game. I tried to bump against the turtle and that ended screw up my camera. You also need re-check your wall collisions and whatnot because I can easily get stuck(I'm able to walk backwards on this one thankfully) whenever I jump over an entrance and into the wall.
That's one example, and in this following webm you have a whole load of other issues especially since there's no menu in-game for a quick reset or checkpoints. You're very much able to fall down(you can't even look up or down with how you setup the player camera controls) and possibly never reset above ground. https://my.mixtape.moe/vgqbab.webm
Game seems interesting to say the least, so I hope you'll take the time to improve your game. Good luck.