Here is the full list of all 33 Cosmic Star Heroine achievements.
Complete the game
A party member betrays you
Use Clarke's Self-Destruct ability
Gain your final party member
Prove your innocence
Defeat the Crystal Wraith
Defeat the Nightmare
Escape confinement
Defeat a cosmic entity
Chat with your party members
Commandeer your own spaceship
Defeat the Blobmith
Reach Lauren's apartment
Charm an enemy
Defeat Spectral Dragon
Defeat the lab guardian
Complete SkyBreaker Tower scenario
Reach 300 Style
Share a soda
Scare rats away in Gehenna
Win a VR Battle
Use a Heroine program
Find the ultimate ingredient
Defeat a special bounty
Win every round of Rock Paper Scissors
Win first battle in game on hardest difficulty level
Defeat the ultimate zombie
Reclaim your high score
Gain Chahn's ultimate ability
Deal over 9999 damage in a single hit
Defeat the Prime Evil
Defeat a true hero
Gain at least 20 recruits for your ship