Use the left mouse button to choose, place, and upgrade towers.
Tower Defense is one of the best classic strategy games that you are able to play online for free. Your mission is to destroy all of the enemies. When you make them disappear, you can protect the village and everybody from their attacks. Before they come and enter your path, you should choose the best places and build up towers. Especially, dropping these weapons properly will bring back more gold. Remember to spend your coins on buying upgrades from the shop frequently! Good luck!