I found that design awful. You start with a pre-built dungeon, can't build anything, and can attract some heroes. 10 to be exact. Then, you have to dig very carefully around the middle where you're ambushed every 4 or so tiles by fairies of different levels.

You can save 3 tentacles, spiders and hell hounds to help you fight the mistresses and witches in the center. I stopped there, the map is very very slow. Fighting the fairies was a pain but they are usually alone except in the south, so my barbarians and monks were able to clean them up. However, when you get to the inner ring, things get very lame very quickly between the witches' wind and the absurd dps of the mistresses. I could have waited with the workshop "economy" to train the wizards but that's not fun at all.

Edit: I just the saw the script, and the mistresses are buffed to 1k health and 255 armour. Witches are also pumped up. No wonder my hounds couldn't do anything to them.