No missable achievements (plus 20 unknown)
Sign in with Steam or Xbox to track your progress, and:
Defeat Big Time Beagle using your noggin, and his
Collect the Sceptre of the Incan King
Buy art in the gallery
Collect the Coin of the Lost Realm
Collect the Giant Diamond of Inner Earth
Collect the Green Cheese of Longevity
Collect the Lost Crown of Ghengis Khan
Get back what Magica stole
Collect $10,000,000
Collect All the Heart Containers on Easy or Medium difficulty
Beat game on Hard
Unlock all art in the Gallery
Enter either underground section of Amazon and climb up the other side using only the pogo jump.
Beat game on Extreme difficulty