best combo for all maps is: shield golem - 2x goblin - healer - 2x goblin -healer -2x goblin - healer - 2x goblin; remember to stun bog towers; i got 59 on last lvl in first try and dint even had 2 try just stun bog and random quakes and heals
use only rockets they almost always hit so you get $ bonus for accurancy every round :)
when you start get atom missle and then invest all in food until you max population 5/5