Nice game :D I like the simplicity of it and it has a nice visual design to it.
I have a couple of suggestions. The first is to add a short explanation to the game page so people know how to play it. It is fairly easy to guess but a lot of people just won't play it if the can't figure it out in the first few seconds (which is one of the main points of the jam!)
It would be great, also, if you could make the score visible at the end of the game. We can't see how well we've done because the Game Over box covers the score.
Is there a way to replay the game without reloading the page?