Pretty simple and fun game. The character is a little floaty imo, but with the constantly changing effects there's not too much time to think about stuff like that.
My biggest complaint is that I often didn't notice when new effects were in play before it was too late! Stuff like the russian roulette or the no jumping is pretty cheeky and I like them, but since I didn't know it was an active effect I immediately assume I'm hitting a bug, which is definitely not the case because the entire game is functional. I'd love if you added a timer or clock that lets me see when the effect is about to change, and if the moment when a new effect is active it is immediately obvious on the gui. More stuff that changes the properties of your gun would be cool too!! Maybe even having multiple effects be in play at the same time too?
There's a lot of space to expand this, but the basics are all here, so here's to you Johnny.