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