I'm afraid I couldn't play much of this game, the aformentioned high sensitivity combined with the psychedelic background makes me nauseaus. I'll grant that it's nightmarish, but it may be a bit too literally so. The models were nice though, for as long as I could see them.

Also, the controls listed on itch.io don't seem right. WASD does nothing, only up and down arrow work for movement, but left and right arrow don't strafe or turn.

At a certain point, when too much skulls spawn , my pc start freezing !

I like the mood, but controls need some improvements. I think you are rotating by either +x or -x (fixed speed), so the rotation is too high for precision aiming. You should use Input.GetAxis("Mouse X/Y") which will return small values for small rotations.

This games main issue is the controls. I think if the controls and camera rotation were fixed this could be awesome! Good work though :D

I agree with yasn below that the controls are quite hard and the camera rotation is quite dizzying. Improving that would make the game more playable.

This made feel drunk :O The controls are a bit strange and the game made me dizzy. :)