Here is the full list of all 29 Phineas and Ferb: Quest for Cool Stuff achievements worth 1,000 gamerscore.
Equipped every customization piece.
Completed the game at 101%.
Completed all of Buford's challenges.
Found every treasure. Way cool!
Found the Mars Queen Crown.
Found the fourth epic treasure: Mystic Monolith!
Upgraded the Museum to "Coolest Museum Ever"
Found the Marvelous Super Agent P Comic.
Equipped the polka dot pink color.
Fully upgraded the All-Terrain Transformatron.
Found all the Lawn Gnomes.
Self-destruct engaged, once again
Equipped the Pizza Wheel.
Helped Baljeet get the A+++ grade.
Upgraded the Museum to "Museum of Ultra Cool"
Found the rare Ducky Momo collectible plate.
Found the third epic treasure: Sea King's Golden Trident
Found Nosey's baby tooth.
Found 40 treasures of any kind.
Equipped the Bouncy Sound Module.
Completed all of Isabella's requests.
Found the second epic treasure: Two-Headed T-Rex Skull!
Found 20 treasures of any kind.
Found the Giant Floating Baby Head treasure.
Upgraded the Museum to "Museum of Super Cool"
Found the first epic treasure: Excalibur!
Found your first treasure chest.
Found your first Lawn Gnome.
Destroyed Dr Doofenshmirtz’s Attract-Cool-Stuff-Inator.