Poor AI and very repetitive missions ruin this game. Very little tactics are employed.
As stated in other reviews, the levels are totally linear. There aren't alternate routes or really any other options that pushing ahead, guns blazing.
There is too much ammo in the guns, because I can make it through a level (albeit on normal difficulty), killing almost every "Tango" myself and still have at least 100 rounds left in my assault rifle. Since you have a team, you'd think that they would need to kill some enemies, at least so you could conserve your ammo.
This brings me to the weakest part of the game: the team AI. Several times when playing through the 16 missions, 1 or more of my team members would become "lost" -- sometimes the entire team. Forcing me to finish the level alone. Not that this was particularly difficult, since you can save at any point. Not only is there the problem with the team following, it is difficult to get them to do what you want during combat. At certain points of the game, I had to tell my team to hold so I could carefully kill the enemies -- they would just go wandering around an area with enemies and get themselves killed. What's the point of the team if they A) get lost, B) don't fight effectively, and C) are probably not necessary anyway?
The story and cinematics in this game are very poor, and worst of all it is very repetitive. Essentially, in this game:
1. you open a door, probably while crouching,
2. shoot a few guys
3. take cover
4. shoot a few more guys
5. move to the next door
then it repeats, and it repeats OVER and OVER throughout the entire game. There is no challenge in get the hostages to safety since you can leave them until the end of the mission, so that doesn't add any variety either.
Finally, while I think most would agree this is a nice looking game, with nice environment and effects, the gameplay itself is boring after the first few missions. It is very generic feeling and uninspired. There is very little (possibly no) use for tactics of any kind. The AI for enemies is just about as bad as for your teammates. I would not spend my money on this game. You can get the same sort of experience playing almost any FPS, and there are so many FPS with so much more to offer.