Here is the full list of all 10 ibb & obb achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Get the highest possible score on all levels.
Find ubb and make him king.
Make it to the party at the end of the game.
Visit all regular and secret levels.
Collect all hidden crystals.
Fall through six different warps without landing.
Bounce a Fin back and forth 10 times.
Get the highest possible score on a level.
Finish a level without dying.
Collect a hidden crystal.