Your mission in this awesome tower-defense game is to protect your gems from being stolen. Place defensive towers strategically. If you save at least one gem (even if it is out of the cave) the mission will be completed. There are 3 different types of towers. Green towers can be build only on grass, Blue towers only on snow and red towers only on rock. If you see UP icon over a tower, click on it and upgrade the tower in the tower’s window.