Bloons Tower Defense Impersonation/Secondary Towers

Secondary Towers are a whole new class of towers. Like Primary Towers, towers of the Secondary class have fundamental properties and attacks that make them great for early-to-middle-game usage. However, Secondary Towers are often unique in the sense that they have special abilities, upgrades, or functions that separate them from the rest. Since the Secondary class itself is unique to BTDI, all the towers that compose it are too.