This game had great potential to smack GTA out of the water in competition. Instead, it delivered a trashy game, filled with bugs, glitches, bad voice actors, and awful boss battles.
The Plot: The plot itself was weak, and un-original. You never felt attached to your character or the agency you work for. Hatred for rival gangs was there, but in the end, you felt your time was wasted playing the campaign. There are 0 SIDE MISSIONS. This was extremely disappointing, and was one of the main turn offs.
The Gameplay: This game is more of a shoot-em up rather than an interesting story. Although it was fun cleaning up the streets, the combat got old by the 3rd hour of playing, and the co-op was useless. The game was described as "the next GTA" by some critics. However, this is far from true. ANY sort of harm to civilians will result in the ENTIRE AGENCY TRYING TO KILL YOU. It really takes away from the free roam game it claims to be.
Scene and development: The graphics aren't too bad, but it felt bland, and old. Even for a 2007 game, Crackdown looked like a budget game, sped up to make a deadline.
Voice Acting: The voice actors were AWFUL, especially the mexican gang. It sounded cheap and vulgar.
Achievements: This game does have some rewards, but not enough to make you feel like your time was well spent.
Lasting appeal: This game had no real replay value. I finished the story in 3 days. 3 DAYS.
Overall, this game is NOT worth your time. If you are looking for a game to play over the weekend, this might be ok, but otherwise, avoid the brain aneurysm this will give you.