The brick in the center is the brick prefab that is being cloned every time a new brick falls from the sky. Usually you delete those and use the prefab from the asset folder directly..
Maybe you could make it so that after the first two or three planes dropped from the carrier, they no longer drop rubys? That way people can't sit and get max rubys on one level
 "Freemium Idle"){kind=icon}
 "Brick 2"){kind=icon}
 "Idle Ants"){kind=icon}
 "Helixteus II"){kind=icon}
 "Bitzy Blitz"){kind=icon}
 "Battle without End"){kind=icon}