Fun, with one or two issues.
This is a good and solid game. There are only two problems that I noticed. First of all, the luck-based success or failure is an interesting feature, but is quite annoying. My other issue is that the final boss' difficulty has more to do with his enormous health bar than actually having him fight back in a meaningful way.
One thing I would say is that, honestly people, there is a weapon switching function. Stop whining about your first gun killing people when you can easily switch to a different, less wide-yield one in about half a second. Three buttons. Right side of the screen. Not that much of a stretch.