how to beat colossus:goblin,hobbit (max pop you can have), and all ranged units with platinum sword or better
that is the only way,if you can build walls too do it,build them in front of him,so he will attack if the goblins and hobbits can't reach him in time,you must make him stay away from your ranged.
any melee unit with the artlogic badge can shield 5 type of ranged units and destroy everything.
and if you have regen spell they are unkillable,fun. XD
nooooooooooo i have completed the whole skill tree but not 100 on every ability! noooooooooo.....
(why there is an elephant in the first cave zone... in the ground?! O_O)
if u leave the enemy pick resources he will launch an attack and start spawning like counter attacks, for stop it destroy the atomic submarines :D i've done this a lot of times
in the final levels.