Strategy for the later levels:
2-5 archers, for picking off the few who get through
1-3 engineers
25-40 wizards
Constantly convert guys. Both in the castle, and with the wizards.... With enough wizards, you can convert one of the group, and then detonate the rest (getting 20-30 kills at a time, including giants, and a convert).... if you have enough wizards you can convert 1 with every wave, if not, 1 every two waves. Doing this (you need to have had a perfect/spend no money except converts rounds 1-10), you can survive rounds 10-16 pretty easily, but then attrition gets to you. Fortification helps, but when I died in 18 I had 38000 hps on the castle.
Giants: Can\'t be lifted, so you have to have archers to kill them, or use wizards blast/kill/convert. They appear after lvl 10, so you will need wizards/archers.
Slow battering ram guys: These are usefull around lvl 7-10, because you can still do those levels without any help at all, so you kill these guys last (there\'s a limit per level on how many guys are on screen). That way you can concentrate on getting 4-5 conversions per level from 4-10, and killing guys by mouse.
Demolition guys - nice idea, but that convert would be better spent somewhere else, same effect as wizards blast, but takes a couple of clicks, and can get you killed (though it can be a last ditch defence if your gate is under attack and your out of wizards).
