I recently played Call of Duty 4 (PC) single player, and was able to complete the game on normal in just less than 7 hours. This isn't too bad, since it was an excellent game, and the multiplayer has kept me occupied for far longer.

BioShock (X360) took about 14 hours to beat, and wasn't particularly difficult thanks to the limitless re-spawn points and no real fear of death.

Army of Two (X360) is the most resent criminally short game. I beat it with an AI partner in less than 6 hours!!!! And if some of the achievements didn't feel like work, I'd have all of them in under a week. Why did I spend $60.00 on a game that I could have beat and finished in one rental? The game was good, but with a limited multiplayer mode, what else is there to do after you beat it?

Ok so short isn't always a bad thing, The Witcher (PC) drags out its game play into a claimed 80 hours by being way too detailed.

Where is the middle ground? I am willing to forgive games like CoD 4 for being short because there is a great multiplayer element. However the games with no multiplayer offer no real incentive for purchase.