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