This is a pretty good game, but there is another bug. While crafting, the music did not play as it should and caused the game to freeze. Reloaded the page only to find that my save and even the auto-save have vanished... there goes a couple hours of gameplay :[
challenge 5 is pretty hard but this strat makes it easy: demolish the farm & coal plant, and build the oil well. build two nuclear plants, nuclear disposal, factory, and landfill. make two garbage trucks & two engineers, and research natural gas.
when possible make a third nuclear plant & 2 metal mines, then save up to make 5 flame turrets in the middle of all the buildings. survive the night, let the oil well die. within the next day remove the garbage from the destroyed oil well, build another, and build 2-3 flame turrets to defend it. you'll probably gonna need farms by now so build enough to even out the demand and build some turrets to defend. from here its easy to defend against the weak enemies with a mix of gun and flame turrets. (oh and build a landfill near the oil well for convenience, as well as 1-2 more garbage trucks, and another nuclear plant to have sufficient energy)
 "Fancy Pants Adventure: World 3"){kind=icon}
 "RPG Shooter: Starwish"){kind=icon}
 "Another Small Favor"){kind=icon}
 "Castaway 2"){kind=icon}
 "Magi: The Fallen World"){kind=icon}
 "Ninja Hamsters vs Robots"){kind=icon}
 "Sushi Cat The Honeymoon"){kind=icon}
 "Super Energy Apocalypse : RECYCLED!"){kind=icon}