Love the mouth sounds. Game is a funny twist on, let's face, one of the most well-known computer games ever. And given that you made in 6 hours it's especially impressive that it's not just the game, and has all the menus and UI elements.
There's not much I would say that isn't just a matter of developing. Giving clicks and explosions a little squanch would make a huge difference, but you can only do so much in 6 hours.