Here is the full list of all 26 BIT.TRIP Presents... Runner2: Future Legend of Rhythm Alien achievements.
Complete 80 Rewards
Beat all Levels in Hard Difficulty
Complete 70 Rewards
Complete World 5
Get one Perfect Run in Each Level
Get one Perfect+ in Each World
Complete World 4
Complete 60 Rewards
Complete World 3
Run a Marathon
Complete World 2
Complete 50 Rewards
Dance 100 Times
Complete 40 Rewards
Unlock a New Character
Beat 30 Levels as Alternate Characters
Complete World 1
Complete 30 Rewards
Complete 20 Rewards
Complete 10 Rewards
Get a Bullseye
Checkpoints!? Who Needs 'Em!?
Complete all 90 Rewards
Get a Triple Perfect+ on Every Level
Get two Double Perfects in Each World
Get three Triple Perfects in Each World