Today an Xbox Live Arcade release sneaked up on on the Marketplace called Battle: Los Angeles.
It's a Konami game, it's about 1Gb in download size and 800MSP to purchase. It seems like a good looking 1st person shooter from Live Action Studios. Product description says:
As the world’s great cities fall, there remains one place that becomes the last stand for mankind in a battle no one expected. It’s up to you to take on an enemy unlike any ever encountered before.
More info and download link here - marketplace.xbox.com/en-US/Pro...