dont know why people find it so hard. the boss levels are a challenge but the rest are very easy. For the turtle: use troops from the crystal huts (speed bonus) to kill the claws, use troops from the tower (+att/def) to kill the head. Dont use normal troops to attack just use them to feed troops to the crystals/tower. Make sure you have upgrades in att/def/speed/agility. The xp upgrade is useless.
*yawn* as someone said since there are NO characters there is no emotional attachment to the alien or farmers. Ooo some pixels 'died' oh the humanity...
speed and survival time are best at the start, but you need the others to survive the gunfire. you dont need survival time past about level 10. the other 4 i had to about 20 by the end. best way to kill rambo (and most heroes) is to buy a bomb and blow him up. That way you get the tank early on.
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