Here is the full list of all 13 Graveyard Defender achievements.
Complete Night 1 with 3 Stars
Complete Night 2 with 3 Stars
Complete Night 3 with 3 Stars
Complete Night 4 with 3 Stars
Complete Night 5 with 3 Stars
Complete Night 6 with 3 Stars
Complete Night 7 with 3 Stars
Complete Night 8 with 3 Stars
Complete Night 9 with 3 Stars
Complete Night 10 with 3 Stars
Complete Night 11 with 3 Stars
Complete Night 12 with 3 Stars
Complete Night 13 with 3 Stars