RoboBlitz

The PC version of RoboBlitz (available for download on Steam) comes complete with a level editor. The Xbox 360 version (available in the coming weeks on Live Arcade) unfortunately, won't. And at this time there is no way to share user-created content between the two versions, though the official RoboBlitz website makes it sound like the developers haven't completely ruled out the possibility.

Either way, RoboBlitz is looking to be one of the more interesting and full-featured Live Arcade games to come along in quite a while - the sort of thing the service should really be promoting. Here's hoping more smaller developers hop on the bandwagon with equally innovative content.