Too fricken hard
I'm stuck on level 8. The game is just too difficult, for three reasons.
Problem 1: Jump and crouch animations have too many frames so that you can't crouch or jump instantly in response to something being shot at you
Problem 2: You get knocked back and stunned every time you get hurt so you can just keep getting stunned until you get away from a bunch of enemies
Problem 3: You get injured every time you overlap the same spot as an enemy, even if the enemy is not attacking