I too am a bit confused with the aim, I see that the balls bounce and damage the areas but I didn't see any effect of shooting on the objects/ball. I think you ran out of time to complete this game.
To improve this game and better fit the theme perhaps you could show some shape that we need to make by breaking these colour blocks and then manually moving them around while trying to avoid the bouncing balls which can also damage the colour blocks. So we would be forced to shoot the balls. That would be a fun concept and also help to adhere to the theme.

I don't really understand what the point of the game is. I think art/theming could've really helped make this more interesting, because the balls bouncing around breaking stuff can be cool.