needs a pause button, example: if your playing apocalypse mode and you need to go to the toilet you have to trust the defenses you have at that moment instead of just hitting a pause button
fun game.. but gem combination should be able to be done in the towers.. instead of putting the gem back in the slots and combining then putting back it to the tower
 "Bloons Tower Defense 4"){kind=icon}
 "GemCraft"){kind=icon}