I see that you posted the game 20 days before deadline, so you definitely had some time constraints. I'm not sure exactly how long you spent on it or how much experience you have, so I'm not going to judge how much you did in the time you had. About the game itself:
Positives:
- Nice background music
- Nice 8-bit style, especially the asteroid and galaxy(?) at the end
- Multiple levels, decent amount of gameplay (definitely better than just one level)
Negatives:
- The gameplay is buggy, the character is able to go below or above the screen, and when you finish the last level it throws an error which forces you to abort (maybe have it go back to the first level when you finish the last level?)
- Gameplay is lacking: it doesn't have anything to do with the theme bug, and you can only move up and down. It's repetitive. Maybe you could add a boost mechanic, shooting, or different kinds of things to avoid (like an enemy spaceship?).
Overall: it seems like you probably made the game beforehand and just posted in this game jam because why not. I would suggest trying the full game jam experience, with the time constraints, theme, and more. It helps broaden your horizons and go outside your comfort zone, which helps you become a better game developer.