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