Here is the full list of all 15 Muv-Luv achievements.
Saw one possible ending of Unlimited
Unlocked Jukebox mode
Saw Miki ending in EXTRA
Saw Sumika ending in EXTRA
Started Unlimited
Took five Drill Milky Punches to the face
Saw Meiya ending in EXTRA
Started Muv-Luv!
Saw Chizuru ending in EXTRA
Saw Kei ending in EXTRA
Saw Common End 1 ending in EXTRA
Saw Common End 2 ending in EXTRA
Saw all possible endings of EXTRA
Saw all possible endings of UNLIMITED
Completed the CG Gallery