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