Here is the full list of all 18 Lost Nova achievements.
Expensive headwear.
Witnessed the righteous fury of Sir Corv.
Made a small friend.
"What a novelty you are."
Reached the lowest level of the Silkgem Mines.
Pumpkin!
Quadrupled the opportunity for science.
Planted flowers.
Pet every bunny in every town.
You fixed your ship, saved the world, and helped out a giant worm. What's next?
Attended a concert of three best friends.
Filled the museum with priceless artifacts.
Shipping and handling not included.
Picked roses for the princess.
"Come on down to Brian's Blasters: you'll love the way you blast."
He pinch.
Pushed a block where it needed to be.
The theme of the game.