In Bloons Tower Defense 4, players are tasked with setting up defenses on a map in an effort to stop a stream of balloons from passing across the screen. At first, players use very simple defenses, but earn money to unlock new powers as the game progresses. The colors of the balloons represents how hard they are to pop, with some balloons requiring heavy attacks in order to be defeated. As the levels become harder, more balloons race through the screen, some of which split into more balloons when popped. The game features no inappropriate content, and reading skills are only used to navigate menus and select towers. Due to the inoffensive content and minimal reading requirements, Bloons Tower Defense 4 is recommended to players ages 7 and up.