A new trailer for tactical game XCOM: Enemy Unknown features CG action, some basic story, and a sprinkling of gameplay. You'd probably prefer a lot more gameplay, but it's interesting enough regardless, and certainly nails the presentation and graphics.
The premise here is you are the commander, and as such, "the lives of the world's best operatives are in your hands. Soldiers will fall, but it's up to you to recruit, train, and advance their skills and capabilities to counter the alien attack and minimize your casualties of war." See it below:
Casualties of War - YouTube
XCOM: Enemy Unknown is developed by Civilization guys Firaxis, and launches October 9 on PC, PS3, and Xbox 360.