Here is the full list of all 26 Runner2: Future Legend of Rhythm Alien achievements worth 400 gamerscore.
Complete 10 Rewards
Complete 20 Rewards
Complete 30 Rewards
Complete 40 Rewards
Complete 50 Rewards
Complete 60 Rewards
Complete 70 Rewards
Complete 80 Rewards
Complete all 90 Rewards
Complete World 1
Complete World 2
Complete World 3
Complete World 4
Complete the game
Beat 30 levels as alternate characters
Beat all levels on hard.
Dance 100 times
Get a bullseye
Get one Perfect in each level
Achieve a Triple Perfect+ in every level
Run 26.22 miles
Skip a checkpoint & beat a level
Unlock a new character
Get one Perfect+ in each World
Get two Double Perfects in each World
Get three Triple Perfects in each World