Here is the full list of all 20 Nyan Cat: Lost In Space achievements.
100 Cow items collected
A UFO abduction survived 100 times
5 pills collected in a game
Ran 25 seconds without collecting any food
Played 10 times on Nyan Cat City theme
100 bombs deactivated
x250 score multiplier reached in a game
5 times jumped over a doggy in a game
Tac Nayn touched 9 times
Ran 1000 meters without touching any kind of enemies
Played in a world other than Space
Stayed on the highest platforms at least for 30 seconds
Stayed on the lowest platforms at least for 30 seconds
A UFO abduction survived
Played with a skin other than NYAN CAT
42195 meters completed
2000 bombs deactivated
20 enemies eliminated with Nyan Love
250 enemies eliminated with Nyan Love
Jumped on Gold Platforms 1000 times