This track has a cog that rotates once every one to two rounds, making the bloons go up, down, or even split between the two. It works in a 5 round cycle: On rounds 1 & 2, the upper path is opened. On round 3, the both paths are opened. On rounds 4 & 5, the lower path is opened. Subsequent rounds continue similarly. If you place towers at the beginning of the track, the upper path is overprotected and the lower path is underprotected.
There is also a section of copper pipe that is too hot to place towers on. In Bloons TD 5 Mobile, instead of being copper pipes, the pipes are see through and there is a purple liquid in the pipes. The heated copper pipe does not appear in this version.
- Main article: Switch/Strategies
- A gear form picture award means the mechanical cog moves.
- Rounds 63, 76 and 78 are exceptionally hard, as the waves of Ceramics will go either way through the cog, making towers keep switching where they are shooting from one side to the other.
- In the files this is called "Go with the flow"