From the introduction: In the world of Bloons Tower Defense, waves upon waves of balloons march towards Monkey civilizations. If these balloons were ever to reach a town or city, it would spell disaster for Monkey kind. Battlefields have been laid out across the world, with Monkey armies conscripted and trained to fight back against the floating menace. You are one such soldier, ready to stand alongside your fellow Monkeys and pop those that threaten your way of life.