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