I'm bad at game development, so this review might seem unprofessional.
Could be more appealing to the eye. Could have instructions at the very beginning, but it still has an easy to understand concept. I'm still glad it's easy overall, too. Unless you get to a score that's above 40+ (I think). Which makes this a great example of games that get more difficult. The idea of others adding pixel art in the game is also nice.