The point of the game is to show how modern social games and MMOs make you take hours to get to something, or just bypass it by paying real money. In this case you can't bypass it.
Walkthrough: Secret Base 2, Russia.
Equip the zombies:
Jayson
Kim Jong il
Michael Jackson
Krugger
1.When the round starts summon a Michael Jackson in the ares with the most armed enemies. 2.Summon the rest of the zombies near Michael Jackson while he dances. 3.Use your virus(es). 4.Use support if necassary
Most bosses can be easily killed by Jayson, Michael Jackson, Kim Jong Il, and several other zombies even if there are hazmats and/or secret agents, but the Jayson/Ramboo boss requires several canister bombs and grenades in addition, or your zombies will get slaughtered.
Go here: http://www.gamezebo.com/games/doodle-devil/walkthrough-cheats-strategy-guide to find the elements you are missing. There are 7 extra because it is the walkthrough for the iphone version.
There are many thing scientifically incorrect about this gmae. First, velocity is the speed AND direction of a moving object. Secondly, at the extreme speeds the paper airplane is flying at, due to E=mc2(can't type exponent), the paper airplane should be gradually gaining mass. Also, even with the help of others, it is unlikey a paper airplane could travel that far without stopping. Lastly, if you put and engine as strong as the one in the game on a paper airplane, the plane would be too heavy to fly. I prefer learn to fly.