Here is the full list of all 34 Mystical Riddles: Ghostly Park Collector's Edition achievements.
Finish a HOP using only the alternate puzzle.
Finish a HOP without any hints.
Finish 3 HOPs without any hints.
Finish 5 HOPs without any hints.
Find 100 objects.
Find 3 hidden objects in 3 seconds.
Find 5 hidden objects in 5 seconds.
Find 10 hidden objects in 10 seconds.
Finish a HOP in one minute.
Finish 3 HOPs in a row in one minute each.
Finish 5 HOPs in a row in one minute each.
Complete 5 mini-games without skipping.
Complete 10 mini-games without skipping.
Complete a mini-game in one minute.
Fix the camera.
Meet Gaby's ghost.
Meet and save Nicholas.
Learn how to remove the barrier.
Release the spirit of the puppet.
Find a usage for the glass eye.
Learn about Nicholas's plans.
Wake Allison up.
Find out how to collect souls.
Talk to Harry.
Learned how to stop the soul collecting.
Diffused the traps.
Found a popular spot in the park.
Got convinced of Spirit's mercantilism.
Talked to a fortune teller.
Learn how to use the camera.
Fulfill the Gnome's wish.
Read the warning.
Find information about cultists.
Prepare the cultists' drink.