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