Here is the full list of all 18 Lost Nova achievements.
Expensive headwear.
"What a novelty you are."
Reached the lowest level of the Silkgem Mines.
Planted flowers.
Made a small friend.
Filled the museum with priceless artifacts.
Shipping and handling not included.
Witnessed the righteous fury of Sir Corv.
Pumpkin!
Attended a concert of three best friends.
You fixed your ship, saved the world, and helped out a giant worm. What's next?
Pet every bunny in every town.
Quadrupled the opportunity for science.
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.