Here is the full list of all 14 Derrick the Deathfin achievements.
Get a gold medal
Get a gold medal in a speed level
Finish level with Derrick in reverse
Finish level in the air with Derrick in reverse
Eat a flock of birds
Eat 100 creatures in a level
Collect all the objects in a level
Complete the American zone
Complete the Asian zone
Complete the African zone
Complete the Arctic zone
Complete all the levels in the game
Collect all the objects in the game
Get gold medals in all possible levels