Here is the full list of all 12 Haunt achievements worth 200 gamerscore. It takes around 3-4 hours to unlock all of the achievements on Xbox 360.
Retrieve the first Phantaflask and return it to the statue
Retrieve the Phantaflask from the Auditory Annex and return it to the statue
Retrieve the Phantaflask from the Luminarium and return it to the statue
Retrieve the Phantaflask from the Motility Vaults and return it to the statue
Complete the game
Defeat one of each type of ghost
Pose for a photo and then admire the picture
Star in a motion picture
Answer the ringing telephone
Complete the game without using a Vitality Vial
Collect every newspaper clipping
Successfully avoid 5 Charger ghost attacks