Here is the full list of all 12 The Fancy Pants Adventures achievements worth 200 gamerscore.
Collect all the customizable items
10,000 Squiggles collected
Win a tournament on your home arcade machine
Get a gold medal in all the Challenges
Get one gold medal
Complete 100% of the Game
Collect all 60 stars
Complete world 1 and 2
Juggle a shell 10 times before it touches the ground
Story Mode Completed
Collect all 9 Message Bottles
Get 100% in one Level