MacD said it for me, nin! The co-op is worth $14.99. I actually played through the entire game with my son and he still plays it today (after almost a year since I bought it). He enjoys the bot matches... HOW 'BOUT THAT... They even put in bots and challenge modes they call it 'arcade' and it's totally different from the single player game. The best way I could describe it is being very similar to TimeSplitters 2 (which received much acclaim for that game's extras) for the consoles. Remember it has it's weaknesses for sure but I overlooked them because they took the time to add so much extra gameplay.
"When all thats left is console gaming, I will game no more."