Here is the full list of all 21 BIT.TRIP CORE achievements.
Achieved a multiplier of 100 in Normal difficulty
Chained 500 Beats
Watched the hidden cutscene
Beat Control in Normal difficulty
Beat the game in one sitting without getting a Game Over
Beat the game on Normal difficulty
Blast 10,000 Beats
Beat Exploration in Normal difficulty
Achieved a multiplier of 50 in Normal difficulty
Play through one entire stage in Super Mode in Normal difficulty
Beat Discovery in Normal difficulty
Beat any level without using a Bomb in Normal difficulty
Chained 200 Beats
Chained 100 Beats
Blast all Beats during a Challenge
Register a high score on the leaderboards
Escaped Nether Mode
Get a PERFECT score in Discovery
Get a PERFECT score in Exploration
Get a PERFECT score in Control
Blast 30+ Beats at once with one Bomb