We need something similar to fire that cools things instead of heating things so we can manually cool stuff down. Call it cold air or frost or fog or something.
I think that mercury should be added! It conducts electricity like metal but it is liquid when hot, or room temperature, but freezes into a solid when cooled!
Penguins and Polar bears in the same place at once...but that will destroy the universe...wait...NOOOOOOOOOOOOOOOOOOOOooooooooooo...........!!!!!!!!!!!!!!*EXPLOSION*
Day 20 is too difficult...needs a save function so that I can easily try day 20 again. It would be awesome if you could upgrade the recharge rate and/or the Tesla Coil's damage. You can increase the mini-coil damage so why not your own damage?