Here is the full list of all 24 Ascii the Brave Cat achievements.
Clear the eastern seaside stage.Hint: press LT(L2) while jumping to do a drop bump.
Clear the graying tower stage.
Clear the sweetest stage.
Clear the ghost ship stage.
Clear the sound of music stage.
Clear the mobile suit factory stage.
Clear the lonely icy stage.
Clear the labyrith pyramid stage.
Clear the dragon head stage.
Clear the no checkpoint stage.
Collects all Hp and Mp upgrade.
Collects all Life upgrade.
Collects all weapons.
Clear game (beat every boss) in hard mode.
Cleared the game without any death.
Win pair card versus mini-game.
Reward more than 2,500g from smash jelly mini-game.
Win N-Queen hard mode mini-game.
Win 01 bet mini-game.
Talk to the whale behind the shop.