A bit simplistic and can be repetitive, but all in all a good, fun game. A must have for any devoted 40K fan!
But this "wear it on your sleeve" shallowness is part of the fun. The "run and gun" gameplay hearkens back to the golden age of Arcade shooters, when we would slap quarters into the local 7-11's stand-up "Heavy Barrel" game until we were destitute and our rotator cuffs began to separate.
The choice of characters is fun, the powers are suitably apocalyptic, and the setting has the great look-and-feel that we 40K fans know and love. In addition, the models in the game are proportioned like the models from the tabletop game... not in the off-putting "realistic" proportions from Dawn of War 2. Space Marines are supposed to be chunky and have some mass!
I could see the action getting repetitive over time; but it is my feeling that by the time it does, you would have well-spent the 800 points that the XBLA download will set you back.
A word of warning, however: those not initiated into the world of Warhammer 40,000 might be a little lost. There isn't much in the way of explanation as to who or what are the major players in Kill Team.
THQ HAS included a "Codex" feature in the game, but it is woefully inadequate to explain the complex 40K back-story. Codex unlocks are extremely thin on the ground, as well... I had been detonating Ork Lootaz for 1 1/2 levels with my Heavy Bolter before the Codex bothered to tell me what the heck an Ork Loota was.
In short, a fun piece of shoot-em-up fluff which works well with the IP. It's not epic or deep, doesn't have any crazy plot twists, and no one gets nekkid. But it's well worth the points, especially for die-hard 40K fans.
Now if you could just play Black Templars...