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