Since it's kinda repetitive, not very replayable, and has a few quirks (basically glitches that aren't really glitches) in it, I rated it a 4 out of 5. For example, mines even work on cops flying in the air. Still, it's a pretty cool game. By the way, NEVER buy the machine gun upgrade...
cool game, NEVER use the shotguns unless all you have is the first gun as an alternative... chainsaw's awesome, but they have to be close enough to be damaging the wall to use it effectively