An interesting level that deals with a wheel mixing water, poison and grass. Have Fun! You’ll want to really pay close attention to some of the very small details in this level. Keep your eyes pealed for the hidden things if you know what I mean.
It’s because you let the green ‘slime’ stuff harden the second wheel under the weeds/grass I think. It happens to me on that level too sometimes if I let the green stuff slosh around. Now you can get through 4-20 with this especially appreciated rebel solution, since on my game the 2nd wheel is solid rock – no sand outlet under the weeds.