The moon gravity clogs the pace of the game, making the game feel slow. So the gravity constant should be raised to remedy that. Jumping animations should also be shortened, and the fps should be raised (to 60 fps, the standard video game framerate) to optimize it so it feels fast paced like it was probably intended to be.
As it stands, the game is too slow. Some side effects of this is that the player gets bored, and the game is too easy. A fast-paced game will be more exciting and challenging, and will stick out and be remembered by players as a fun experience.
As Shigeru Miyamoto once said in a hilarious reply letter to Chris Chan, "Video games are a medium where you must think of what other people want"
Anyways, if you do decide to optimize the game, then I wish you luck.
 letter is here: https://images.encyclopediadramatica.