Here is the full list of all 27 KAMIKO achievements.
Pressed the switch to open the first door
Unleashed all 3 of the playable characters' Special Attacks in one save data
Defeated 15 enemies in one stage
Chained 100 combos
Broke a seal to a gate between worlds for the first time
Found secret item Sushi
Opened 4 gates between worlds
Cleared The Forest of Awakening
Found secret item Hamburger
Cleared The Sunken Relics
Found secret item Crow
Cleared The Scorching Labyrinth
Found secret item Doll
Have a playable character with max stats of HP12 and SP400
Cleared The Ruins of Yamataikoku
Cleared playing Yamato
Cleared playing Uzume
Cleared playing Hinome
Killed 3000 enemies in one save data
Destroyed 1500 objects in one save data
Cleared game within 30mins
Cleared the game within 30mins for each of the 3 playable characters within the same save data
Found all secret items within the same save data
Unlocked Sound mode
Didn't use Continue to clear the game
Cleared the game with no damage
Unlocked all Achievements