If you've played through Heavy Rain, you know that most problems can't be solved by shooting a dude in the face. For GTA IV's Niko Bellic, that's very much a real problem solver -- a tactic he has no problem using. So it's a pretty odd juxtaposition to see the two games spliced together like they are in the video past the break.
It's a pretty great video, but we feel we should warn you that you probably won't get it if you've never played Heavy Rain. Unless you're watching this part, which we're pretty sure is funny no matter what game(s) you've played.