I've given it a 3/5 because the graphics are awesome and the overall concept of the game is really impressive.
But as mentionned below, the game is quite slow and repetative.
Also, i think death or game over screen should be removed completely, considering the simplicity of the game most deaths are probably only caused by mistake or bad timing. So if someone dies it's going to be really frustrating having to start all over again.
Try adding checkpoints or instead of dying you could just get hit back a bit.
Other than that, good game!