bloons td 6 is a 2018 tower defense video game. it is the sixth game in the "bloons td" series. it was developed and published by ninja kiwi. it was first released in june 2018 for ios and android. the game was later ported onto steam. it was first released on microsoft windows in december 2018. it was released on macos in march 2020. it was added to apple arcade on february 11, 2022, as bloons td 6+.