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