Cute game!
Some suggestions for improvement:
- When dying, sometimes the screen keeps scrolling to the right endlessly. You may want to add some sort of collider below the bottom of the screen to stop player movement on game over.
- Add a way to return to the title menu from the main game screen. Pressing Q or something like that would be fine.
- The restart button should be selected when it shows up on screen so that the player can just keep pressing Space bar to try again.
Good job!