Nice, nice and satisfying sound effects too, but idk if you made those.
Also, I liked the atmosphere, maybe you could also add some footstep sounds with some echo to make it even more moody.
I didn't really understand why if in mid air you press left or right after propelling with your gun, you get reset to the movement speed you have while on the ground instead of continuing to go at the same speed you have while in mid air... I believe that's because you set your character's speed to the fixed movement speed when you press left and right in your game's code, but I think you should either disable air control after propelling with your gun or at least let me go at the same speed.
I couldn't get very far in the game cause I got stuck without being able to reach a high up platform at some point, but I still enjoyed the game, good job :D