Fun but repetitive, with a sudden jump in difficulty.
The graphics are quite mixed up, some objects have good models but low res textures, while some have nice textures but blocky models. Enemies are mainly only differentiated by what kind of weapon they use, which probably worsen's this game's one major flaw: repetition.
You'll be doing the same things over and over. The only reason the level of repetition in this game is acceptable is because the game is so simple. Headshots are easy, but there are also quotas for headshots. You also will soon not be able to complete all the goals of a mission on one playthrough. Add to this the fact that the standout weapon is the pistol, and you'll be wanting to use it nearly exclusively, so ammo conservation is a must. The conservation effort will push your towards the sweet and easy headshot. When all of this comes together, the game may start to grind your gears at about the halfway mark.
Around that same halfway point is a jump in difficulty. You'll notice instead of two runs through a level to get all the goals, you may be doing two or three, or more if you die a lot (and trust me, in some levels you will,) because every level has a goal that requires you to complete the level without any continuations.
On the plus side, the voice acting is very good, the level design, pacing, and art design are fantastic. Even though the story is a thinly veiled jab at Bush, it's still interesting enough that you probably won't be skipping the news reports at the beginning and end of the missions.
Controlling your character is a breeze, and giving commands to AI characters is responsive and simple.
This game is fun and simple, and I would recommend that everyone at least give it a try.