I've been playing the campaign up to level 10 now.
it's astonishingly like dungeon keeper 2. lawsuitingly like dungeon keeper 2. same voice actor. same general principles, but with alternate themes.
hatchery --> micropiglet farm
Training room --> barracks
prison --->prison, only it doesn't make skellitons. it just stores guys
it seems to have more kinds of units, more functions. each trap has 2 modes of action. instead of just spells you now have spells, rituals, constructions. rituals requires guys to pray at the temple for a while and it makes a big effect (all the walls are finished in the dungeon). constructions are items that are not traps. like a box that teliports gold dropped in it ot hte dungeon heart (wait, i mean dungeon core!), or new wall segments.
capture units in the prison, drop them in the torture chamber to convert them, torture them to death to make them into shades (invisible scout units), grind them up into food in the tavern, cast blood money on them to turn them into a block of gold (instead of 'create gold spell').
there's a big talent tree thing for...i suppose sandbox or survival mode. your cultists research it in the archive.
so basicly it's like a 1 for 1 remake of the mechanics of DK2, with new style to everything, added features, and it's own campaign. So if you have DK nostalgia it's a great game. I like it a lot, but it's not an evolution on the DK franchize, it's the same thing again. I'm hoping they build upon it in the future.