Square Enix has made it possible to enjoy the excellent Space Invaders Infinity Gene soundtrack, by Taito "house band" Zuntata, for use even outside of shmup-related activities.
The publisher has released the album on CD, the Amazon MP3 Store and iTunes (and mora in Japan), bundling all the tracks from the iPhone and XBLA/PSN releases, plus the iPhone update, into a single music collection. The CD edition also includes "a visual reference guide/sticker sheet depicting all 90 characters from the game."
This is the first simultaneously digital and retail release for a Zuntata album; if you want to know why that's so awesome, we suggest listening to some preview tracks on iTunes. That way, you'll hear how cool the music is and realize you didn't have to mail-order a $50 CD from Japan.