Hello everyone! I am working on my second Android game. So before further working on it, I'd like to hear something from you (basically getting feedback).

Concept: There are several levels and you have to shoot boxes to proceed to next level. There are several types of boxes which can give you some special power or ability. The more boxes you shoot, the more is your score and you unlock several items. As soon as you reach at some required score, you reach next level.

I think you all can add your own elements here so that I can get some really good suggestions. Please share your ideas or improvements for this!