Shooting and killing are very satisfying thanks to the sound effects. The only issue I really found was the instructions on how to play. My first time playing I was more concerned with surviving and shooting so the text went mostly ignored, then my second play when I felt more comfortable with the flow of the game I read and understood them. After that they just kind of got in the way. I think you did a good job of presenting them in a cool way, it's just that maybe it should only be on your first playthrough and it should pause and let you read it.
A really fun game that feels good to play nonetheless, good job!