The series offers different levels of complexity depending on your mood:

Bloons Tower Defense is a popular tower defense game that has been entertaining gamers for years. The game involves popping balloons (or "bloons") that are trying to escape from a path by using various towers with unique abilities. However, sometimes you might not have access to the game due to restrictions at school or work. That's where Unblocked Bloons Tower Defense comes in.

The persistence of unblocked BTD is a testament to a low-stakes arms race between network administrators and resourceful users.