Here is the full list of all 26 BIT.TRIP RUNNER achievements.
Beat all challenges on Perfect difficulty
Get the Game Over
Watch the hidden cutscene
Complete Triumph
BURGER MOUTH
Complete The Gauntlet
Repel 100 Beats
Find 3 friends and beat the challenges they are in
Complete Tenacity
Catch a fish!
Complete Impetus
Complete a level in one sitting
Complete Odyssey
Jump 1,000 times
Collect 1,000 Gold Bars
Get a PERFECT on one challenge
Get Bonked by a monster
Bonk after missing a Gold Bar to rewind time and try again
Roast your mallows over a campfire
Register a high score on the leaderboards
Complete a bonus challenge
Get CommanderVideo's cape
Get a PERFECT score in all Impetus Challenges
Get a PERFECT score in all Tenacity Challenges
Get a PERFECT score in all Triumph Challenges
Get a PERFECT in all challenges