Here is the full list of all 17 Corpse Party achievements.
Attained all endings and found every name tag.
Attained the alternate ending to Chapter 5.
Viewed every ending.
Attained the "loop ending" to Chapter 5.
Attained the true ending to Chapter 5.
Attained all endings in Chapter 4.
Completed Chapter 4.
Completed She Knows a Key.
Completed Tooth.
Completed Meeting of the Minds.
Completed Chapter 3.
Attained all endings in Chapter 3.
Attained all endings in Chapter 2.
Completed Chapter 2.
Completed A Gentleman's Errand.
Attained all endings in Chapter 1.
Completed Chapter 1.