Co-op fun to be had
It's been said before, but a 50 Cent game doesn't have any reason to be this good. Not that's it great, but you could do much worse in the action-shooter genre on the 360.
Take a serviceable 3rd person shooter, add gratuitous amounts of G-Unit style, and tack on a combo scoring system. The result is a silly romp with big guns, big rides and bigass ramps that is worth the 6-8 hours you'll spend with it. The time spent with this game is worth much more if you play co-op with a friend online.
At an asking price of under $20, I have no regrets picking this up. And as far as achievements go, this game is an easy 1000.