Here is the full list of all 10 Gav-Gav Odyssey achievements.
Collide with spikes
Collect 50 diodes in one run
Collect 200 points on a spaceship
Collide with a rocket on a spaceship
Complete the game on the difficulty of "Expert"
Release the dog named "Snowball"
Release the dog named "Coal"
Face the masked monster
Protect the dogs' waste
Collect 20 diodes in one run