Here is the full list of all 14 Clea achievements.
The base game contains 13 achievements, and there is 1 DLC pack containing 1 achievements.
Completed chapter 1.
Unlocked a bronze, silver or gold reward.
Completed chapter 2.
Completed chapter 3.
Completed chapter 4.
Completed chapter 5.
Completed chapter 6.
Reached the bad ending.
Reached the good (incomplete) ending.
Reached the good (complete) ending.
Completed chapter 1 on Chaos Mode.
Completed chapter 1 in under 3 minutes.
Completed chapter 1 on Arcade Mode.
Completed chapter 1 in War Maiden Mode.