good game! It was challenging at first but then it turned into: start level click once with the infection and pick up as many coins as you can before the town is destroyed and the window closes.
easy all you have to do is put down 2 or three rows of the 1000 volt things around their spawn and then just pick off the few enemies that get through. Also it is Amperage that kills not voltage.
level 21 is too easy. you can just use deck peices conected end to end and it doesn't break. also it annoys me that steel can magically travel through the ground and doesn't react to the environment.
survived to day 13 then fell to the horde of unidentifiable blobs that for some unknown reason have it out for elevators but didn't just attack the powerlines.