The blue button, sometimes called a tank button, reverses the direction of all moving tanks, with some exceptions, in the current level when stepped on. If there are no moving tanks remaining in the level, with one of the same exceptions, the blue button has no effect.
Tanks will not be reversed if they are standing on ice or force floors, unless Chip touched the blue button on his initial move, or landed on it after sliding over one ice, force floor, or teleport. Tanks standing on clone machines will only switch in the MS version or the most recent Tile World emulation, and only under specialized circumstances. When this happens, the Frankenstein Glitch has occurred. This glitch is seen in David Stolp's table of contents and ode to a cloned tank, pointed the wrong way. (More information on exactly which turn the tank reverses can be found on the main article for the tank.)