Just a Suggestion
I think the game is very well built.
My suggestion is that instead of having lives, because that only makes the game more frustrating, have time instead for each level.
Then once you beat a level you can go onto the next and make a menu where you can play any level that has been unlocked to try and beat your previous time.
Once you have beat all the levels you can submit your total time (all the level times added up) to a highscore board.