By Date By Rating
Beat Hazard [Steam store page]
An interesting mix of music and gaming - enemies generated by songs. Disappointing that they charge extra for multiplayer (DLC - BH Ultra).

2D • Action • Arcade • Bullet Hell • Casual • Co-op • Colorful • Great Soundtrack • Indie • Local Co-Op • Multiplayer • Music • Music-Based Procedural Generation • Replay Value • Rhythm • Shoot 'Em Up • Shooter • Singleplayer • Space • Twin Stick Shooter • Link