Uhh..
It's not terrible. I didn't know what to do at the flag, because nothing really happened. It's either a bug or you have to hit some sort of key, but I'd add an instructions page to help people. Also, please add a background. The white background is just plain boring. Aside from those two points, it was quite fun. I'd recommend adding instructions/fixing the bug (which ever one it was) and add a background, then resubmitting.