Here is the full list of all 15 Double Fine Happy Action Theater achievements worth 200 gamerscore.
You've got a big living room!
You destroyed 10 or more objects at once!
You scored more than 999,999,999 points!
You found the Purple Tootfish!
You found the magic belt buckle!
You grew 200 flowers in your garden!
You did the worm!
You destroyed 10 wizard platforms!
A Zeppelin has been taken down!
You hit the camera with a snowball!
You selected a stage hand!
You found the Disco Critters!
You got 6 pigeons to perch on you!
You've been completely submerged in lava!
You're awesome!