yeah its pretty much like left 4 dead with the AI and the gas cans, but its gets very boring after you beat all the heists. the AI is brutal its almost a must have to play with friends.
For me I think the game is not worth it! Maybee it's any good if you play it together with friends. I thought it has some kind of a single player storyline but nothing. You can only choose which "heist" you want to make and up it goes. I also don't know how to save and pause the game (at least on PC-version). Besides that you usulay have to wait a long time until a device of you such as for example a drill goes all the way down or terminte burns itself thru a wall.
I think they could have made a very awesome game but stoped in the middle and released just something.
It's a very solid co-op oriented game. However as others have said, it can be brutal playing alone. If your a fan of Left 4 Dead, Killing Floor, Kane and Lynch or Hollywood Crime films its a must have. I can say personally I felt it filled a gap in gaming and is a welcomed addition.Hope this helps