The Lost Colors Add-on for Groove Coaster has 6 achievements.
Play Lost Colors 20 times
Play Lost Colors and clear all of SIMPLE, NORMAL and HARD
Play Lost Colors and get A Rank in SIMPLE, NORMAL and HARD
Play Lost Colors and get S Rank in SIMPLE, NORMAL and HARD
Play Lost Colors and get S+ Rank in SIMPLE, NORMAL and HARD
Play Lost Colors and get S++ Rank in SIMPLE, NORMAL and HARD