The only levels I have left to 'perfect' are the very last level (goddarn Cultists) and the fifth challenge- and, naturally, the Endless thingie. But I'll get to that.
The final level I can at least see the possibility of victory in- it seems with enough (ridiculous) micro, you can make it through. But I've no clue how to get past the fifth challenge. Around wave 40 of 45, I have all my troops out, in my optimized layouts, ready to cruise to the end. Then the nine splitters (that hit for ~350) roll in. They focus down defender after defender- they melt them before I can heal, either with the spell or healers. And Cultists arrive, and swarmers of River Ghouls, and my entire defense gets ravaged and chewed up. I have all armors fully upgraded (I need the last Obsidian Skull for Eye of the Flame+) and all people equipped with max armors, and STILL get massacred. How do you possibly hold...? My main characters are all 60, and all my generics are ~49-54. I'm using Shock Lightning and Slow End. Do I have to use the Explosive Start bomb tactic to win...?