Here is the full list of all 26 Just Shapes Beats achievements.
Get 25000 Beat Points
Complete a playlist of 10 songs or more
Complete 100 challenges
Complete a playlist of all bosses
Rescue 250 friends (Challenge mode)
Obtain Rank S without dashing
Get 7500 Beat Points
Obtain 15 Rank S
Rescue 50 friends (Challenge mode)
Complete 50 challenges
Obtain 20 Rank A
Dash 2500 times (Challenge mode)
Obtain 10 Rank A
Get 2000 Beat Points
Complete 25 challenges
Complete a level without dashing (Challenge mode)
Obtain 10 Rank B
Dash 1000 times (Challenge mode)
Complete a challenge with Rank A or higher on all levels
Complete Story
Beat 'Final Boss' (Story mode)
Beat 'Close To Me' Boss (Story mode)
Beat 'Lycanthropy' Boss (Story mode)
Beat 'Barracuda' Boss (Story mode)
Beat 'New Game' Boss (Story mode)
Beat tutorial Boss (Story mode)