Poor instructions. The game starts to soon after you press enter. A countdown would be nice. To restart you have to click, and then press enter. Totally unnecessary, especially since you have to do this every five seconds.
And all this just to make an exact clone of an existing game.
This is not a game. It's a programming exercise. I could give the actual game the grade of 2.5, but combined with the above flaws I can't.