Here is the full list of all 20 Paranormal State: Poison Spring achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Complete the main story.
Finish a Hidden Object scene in less than 1 minute.
Finishing a Hidden Object scene without a hint.
Enter the ritual cave.
Draw your own map.
Escape the haunted trailer.
Complete the Talking Stick.
Escape the excavation pit.
Use the EVP recorder.
Finish a total of 10 Hidden Object scenes.
Use the CAM.
Finish a total of 10 minigames.
Discover the Old Zeb.
Escape the basement.
Finish 3 minigames in a row without skipping.
Use the EMF meter.
Finish a minigame without skipping.
Finish a Hidden Object scene in less than 3 minutes.
Finish 3 Hidden Object scenes in a row without a hint.
Find 20 wolves.