Gravity Byte may be a great app. But, it does not make a great first impression. You may want to try to give the app a more cohesive art direction. For example, in the app screenshots, I see 4 different fonts. Also, the game graphics don't really grab my attention. Keep in mind that most people are judging your app almost entirely by the screenshots.
You could probably turn that around rather easily by paying a good designer or graphic artist to produce some professional looking assets and reskinning the game.
