Omega Five! Great little shooter. The Xbox Live Arcade game features an unlockable "retro mode" where the game's graphics and the sound go 16-bit! You know what, that's pretty neato. The score was done by game music vet Hiroyuki Iwatsuki, who apparently has been inspired more by game music than anything else. (Word has it he hadn't even heard the Beatles until he started working in the game industry!) Iwatsuki says this about XBLA:
As far as video game music is concerned, when the service first started, we either had to limit the number of the tracks or use built-in synth to play each tune in order to accommodate the capacity restrictions. I think that most of these technical problems can be solved now because of recent improvements in the technology. I think that it would be truly interesting if games come about using the powerful sound capabilities of the Xbox 360 while incorporating a system that manipulates sound in real-time so that the music interacts on a deep level with the gameplay.
We think it would be truly interesting if more developers like Natsume made high quality XBLA games.
Omega Five Interview [Siliconera]