So I played your game and I have some feedback for you.
- Sometimes enemies spawn to close to you.
- Sometimes when you colide with them you don't lose for a while
- When you jump the enemies float kinda weirdly. Mayby don't let them jump or tweak the numbers?
What I would recommend you changing/adding:
- Maybe try adding some background.
- Add some particles to the bullets or enemies' death.
- It would be nice if the camera would shake after kill.
- Maybe try creating more elaborate menus. Because now it's just plain text.
Don't get me wrong, the game is neat and I like it. You did some things very good and some things need a little bit of more work but that's okay. The game was made in 3 days I uderstand that is not a lot of time to create a project. Try improving on your games and keep going.
Overall pretty fun game!