Here is the full list of all 25 Poi achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Beat the game in New Game+ mode.
Take a picture of the Master Explorer.
Take a picture of ALL the creatures.
Collect ALL the Explorer Medallions.
Find all of the hidden costumes.
Find ALL the Golden Gears.
Visit the hidden planet.
Find the legendary treasure.
Meet the requirements to open the Mysterious Gate.
Discover ALL the Locations.
Find ALL the Fossils.
Collect all the Explorer Medallions in Crystal Cavern.
Rescue all the baby Pin Birds.
Collect all the Explorer Medallions in Sinking Sands.
Collect all the Explorer Medallions in Mount Magma.
Kick a Bucket Head.
Collect 10 Explorer Medallions.
Collect all the Explorer Medallions in Cozy Canyon.
Find a hidden hat.
Discover the mysterious travelling merchant.
Do a triple jump.
Purchase an item from the shop.
Sometimes, things don't always go as planned.
Earn your first Explorer Medallion.
Hey, watch where you're rolling!