This is a tower defence game, so enemies spawn at the yellow square and travel along the green path to the red square. Enemies can be killed by towers. Click on a white square to select it, then click on an option at the top to build / sell / upgrade a tower on the selected square, then click on a non-white square to deselect it. At the start of the game you will have 20 coins to build towers, then when you are ready you can press START when no square is selected to start the enemy spawning. When an enemy is killed you get some coins.
