Cute game.
For whatever reason I always enjoy this genre of games (if it's not excessively slow to progress, which this game wasn't). That said, it doesn't really seem to have any unique twist or anything.
The transition through the upgrade tree, from having so few bubbles you click them all as you spawn, and so many they fill the screen, is very abrupt. I ended up with so much money from one run I could just about buy out the entire (non-locked) tree.
It also felt a bit weird that fixing the ship gives you nothing (presumably) until it's all the way done, so it never seems like you have much reason to do it over actual upgrades, until the end.