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.
Enter the ritual cave.
Draw your own map.
Escape the haunted trailer.
Complete the Talking Stick.
Escape the excavation pit.
Use the EVP recorder.
Finishing a Hidden Object scene without a hint.
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 a Hidden Object scene in less than 3 minutes.
Finish 3 minigames in a row without skipping.
Use the EMF meter.
Finish a minigame without skipping.
Finish 3 Hidden Object scenes in a row without a hint.
Find 20 wolves.
Finish a Hidden Object scene in less than 1 minute.