This is good fun provided you can find others to play it with, just be warned it's got several broken achievements and the round wins + cash stolen statistics aren't tracking properly. Acting like an NPC is challenging when you're playing as the robbers, as inevitably one of the Cop players decides to start firing rounds right past your head to see if you jump and give yourself away.

While this has single player, once you trip the fire alarm or blow the first safe, the Cop NPCs lock on and find you fairly fast. They're also (as far as I could tell) invincible bullet sponges - 6 shotgun blasts to the face won't touch them, so obviously playing as a class equipped with a pistol or SMG means forget having a gun.