Here is the full list of all 12 Bliss Island achievements worth 200 gamerscore.
Win all the silver medals.
Win all the bronze medals.
Complete all the gold levels.
Complete all the silver levels.
Win a game of Multiplayer Forest Frenzy 5-0.
Win a game of Fluffy Football 3-0.
Complete all the bronze levels.
Win three medals by completing three tasks.
Complete Brick Invaders in adventure mode.
Win a medal by completing a task.
Complete Fruit Smoothie in adventure mode.
Win all the gold medals.