In challenge 22 I thought you had to damages 2 enemies with all weapons, but my friend Res0. =D Told me you have to kill 2 enemies with every gun. 2 kills with anti-freezer, 2 kills with boomstick, 2 kills with twister, so on... so yeah. ._.
Damn That Turtle Was Strong, I Had Like No Towers So I Had To Get My Men To One Tower And The Other Quick Before It Got Hit, And Had To Fight The Turtle With A Twister While Do All That. o.o