The game is definitely lacking juice.
And it's got a few technical problems:
-If you press both keys at once and then hold 1 of them, the game doesn't move your character in that direction. So you're left holding the button and nothing is happening.
-If you press space, both characters do a little glitchy jump.
I do like the idea, it's short and cute, it's something I could play with my son.
Give it a bit of juice and it would be more satisfying to play.