Subterranean Sewers
Subterranean Sewers is an Intermediate Difficulty Track for Bloons Tower Defense 4 Expansion which represents a sewer, hence the name. Along each row of pipes are two entrances and two exits, marked also by the gaps along the pipes. This track suffers the Locked Bloons bug, where the bloons won't come out even if you press the "start round" button.

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