Normally, one would associate (often incorrectly!) that the Xbox Live Indie Games Channel was a place for hobbyists, or beginners, where the ugly mixes with the crude for a bargain price. Not so. Especially in Orbitron: Revolution's case.
Being developed by Firebase Industries (and with music by Audio Antics, of Geometry Wars fame), it's arcade classic Defender for the 21st century, and was recently handed in for the Dream Build Play 2011 Challenge.
Sharp Mode [GameSetWatch]
UPDATE - Just to be clear, while this is currently still in development and slated as an Indie game, by virtue of being entered in the Dream Build Play 2011 Challenge it could win a chance at becoming a full-fledged XBLA title.