It's fun, but it gets kinda repetitive after a while. A couple of unique enemy types other than 'run at the player and shoot what I'm carrying' would go a long way here.
Also, for anyone playing, vampire and dynamite are absolutely essential to pick up, get stolen hand and shot upgrades after that.
I reached around 20 upgrades in one run before I got bored (also, game lags too much at that point)