Suggestions
A nice addition would be to have score-based goals and levels so that the game has something for people to work towards and it gives the game a sense of having a story-line. As another suggestion, why not try to expand what you are required to do in a game as opposed to JUST gathering stars, such as a competition between a player and a computer opponent to see who can gather the most stars or to see who can survive the longest. These are just a couple of ideas I think would improve the game experience.