Solid gameplay loop, and gets pretty fun once you're in the swing of it. Can be very unforgiving if you miss a shot at low health, or get suddenly hit by an enemy (which feels unfair when they spawn on top of you). Music and visuals worked nicely, and kept the game feeling lively.
Could've used some light tutorialisation at the start, since for my first few runs I didn't realise I was using my own health to shoot and kept just suddenly dying. It also took me a while to figure out I could hold left click to fire, which finally stopped me from accidentally clicking into an upgrade choice when they appeared.
I liked the variety of upgrades on offer. The Devil's Hand always seemed to be the best option when I wasn't in need of health, and it was cool to be able to manage the drawbacks each level up. Overall a great entry!