Here is the full list of all 13 Aeon achievements.
100 head shot.
Used your sword to slash a bullet.
Used your sword to slash a rocket.
Slashed 100 enemies/rockets/enemy pieces
Killed 100 enemies without dead in endless.1 mode.
Killed 100 enemies without dead in endless.2 mode.
Finished all levels in Easy Mode.
Finished all levels in Normal Mode.
Finished all levels in Hard Mode.
Finished all levels in Nightmare Mode.
Finished all levels in Mars Mode.
Finish 20 battle points without hurt.
Finish all levels with expert mode.