Here is the full list of all 12 Demon Hearts achievements.
Complete game with Snow.
Complete game with Chata.
Complete game with Angel.
Complete all main levels with all characters.
Defeat the Final Final Boss.
Find The Secret World.
Kill Verdus without killing any of his minions.
Defeat Azuro in Demon Mode.
Defeat Verdus in Demon Mode.
Defeat Rojon in Demon Mode.
Jump 9000 times.
Kill 666 Demons.