In the upper left of the screen is your energy. If you get hit by a bomb or run over a man you'll lose energy. The longer that you're in the explosion of a bomb, the more you're tank will get damaged.
You can kill the running people four ways. You can simply run over them, shoot them, let the explosion of a plane's bomb hit them, or shoot the plane down so the plane will crash into them.
ツ This is the GS-257 Battle Tank "Devastator". You use this to kill . everything that moves.
ツ This is a German Soldier. They are unarmed and harmless.
ツ This is an RU-90 Power Jet. They were specially designed to . . . . counter the Devastator.