had a good 4 hours play on the single player of this today (360 version) managed to do the first 2 campaigns, so i think people who are completing the game in 2hrs must simply be running through each mission or something and not properly playing it.
it was great to finally see what happens after the demo ends! some fantastic set pieces in the campaigns ive completed, which of course i wont mention here! havent tried online multiplayer yet, will be doing that tonight, no doubt into the early hours.
i love the whole "movie" style of the game, from the poster to the end credits that roll, telling you various stats from your mission. B)