This game is great!!!
You play as a captured soldier named Keller. The game is actually a flashback as you review the events of what occured. The enemy is some terrorist group called the Seventh Wave, that looks like a combination of towel-heads for the lesser guys and Ghost-Recon (the original)-esque style bad guys. There isn't a huge variety in bad guys. Theres the average weak guys with the entry-level assault weapons. Then there are the stronger guys with body armor and higher level guns. Then there are the super-freak body armor guys that take two to three shotgun blows at point blank range.
The AI is actually really good unlike what Gamespot says. The entry-level grunts will perform basic maneuvers such as hiding behind things and trying to flank you. The higher level guys direct the lower level ones and possess more intelligence. The badass guys just rush you with a shotgun or get you at longer range with something bigger.
My only real problem with the game is your stupid radio. At random times when you're trying to be quiet, you just yell into your radio and the person on the other end yells back. The radio messages come pretty randomly it seems and the majority of them make no sense and don't have anything to do with the mission.