When I bought this game, the girl at Gamestop actually said "I have to warn you, there's a mandatory 20 minute install before you play the PS3 version." I appreciated that she wanted me to know ahead of time, but at the same time, feel kind of like "If you can't afford 20 minutes out of your life to install a game, you need to manage your time better." I mean, it takes about 30 minutes to beat a mission anyway, so if you can't even spare 20 to install the game, there's not much hope of you ever beating the game without leaving your system on anyway. And if you're going to do that with the 360 version, I'd be a little leery of the system RRODing while you're gone, lol.