click the shop tab and if you have enough money to buy a tower (price and descriptions below them), you can click on it then click somewhere else to place it,you can't stack towers or block the track or place more than 3 super towers beat wave 38 then click next wave to win. if bad guys reach the end you lose health corresponding to the bad guy's health. running out of health is bad feel free to create your own challenges like tower placing limitations!
