The Halloween 2020 Title update for Tower Unite has 11 achievements.
Find Lil' Pup
Buy every Ghoulcery item
Befriend the Halloween characters
Collect 100 Ghoul Coins
Deliver 50 remains
Deliver 100 remains
Uncover the 10 hidden bones in the Plaza
Collect 50 candy
Find the haunted treasure
Open a Halloween catsack
Find all 131 Jack o' Lanterns in the Plaza