It's a fun sandbox. I tend not to stick too rigidly to following the missions, despite the intention to progress them each time I start it up. If you can get a few people together definitely go for it. If you like sandbox games where you're destroying stuff, grappling onto and hijacking helicopters and jumbo jets, and generally causing mayhem for the military forces, then it's even worth it at it's non discounted price. The DLC are a bit hit and miss. I'd suggest playing the game first before deciding which if any of them you want to get. Note that it only works on Vista and Windows 7 however.