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