Click/tap an empty spot (circle) to place a tower, click an existing tower again to upgrade it. Keys 1-8 also work. Progress auto-saves โ you'll get Resume!
Leave mid-game and your progress stays saved on this device โ when you come back, you'll get a Resume or New Game button.
Welcome back! ๐ฟ
Your last game is saved on this device. Resume it, or start a new game?