It's a good game overall. It really is, gives almost as much enjoyment as previous iterations. So why the thumb down? Because there are issues which I'm not willing to see in future releases of this game, nor in any other games for that matter.
There are reviews saying that the developers completly ignored the community. I personally don't care if devs are listening to community or not, as long as they're good enough to release a consistent product. Which this is not. In far too many places it looks like the devs (level designers mostly) were thinking "ok, here's a draft of a level, I'll save it now and finish it some time closer to the deadline", and then never did.
First catacombs are ridiculously lined with eggs along the corridors walls, just like someone would launch a level editor and made click, click, click, click to spray them in few minutes and voila! We have a level!
On Whitehill there was not enough will to do even that, it's just a barren land with a couple of enemies and badly aligned textures.
Aralan feels deserted even thought there's no reason for that in the story, it's an Elven mainland!
Most other levels are ok, but from time to time you'll see things that strike you how someone couldn't be arsed to finish something on a decent level.
You don't release something in such a merry state, they should rather cut such unfinished content alltogether. Now it's like a lovely pie with a ball of poo on top instead of a cherry.
Then there are bugs. Not game breaking ones (I haven't had even a single in-game crash), rather little or bigger annoyances. Like inability to have an aspect-ratio correct display with sharp graphics (everything gets soft-scaled with some blurry filter), unless you switch your monitor to game's native resolution (1680x1050) without scaling, which makes things look better (but still not perfect). Or crashes when you switch resolutions (had to edit the configuration file manually). Or crash on every exit. Or some badly working spells. Etc.
The point is that it's not that the devs ignore the community. They outright abandoned the product - there were practically no meaningful patches, and probably never will be.
What annoys me most is that publisher is now probably sitting there scoffing "we released a 20% unfinished product and look how it sells! lets make the next one 60% unfinished, straight in the customers face hahaha!"
And they will charge it 30 euro, with 60% of levels being deserted whitehill lined with eggs, provided that you'll get out of washed-out main menu without a crash, to be fixed with the next patch, which will never come. And we'll buy it.
And that's why I thumb it down. To have the next King Bounty as well designed as The Legend, as bug-free as Crossworlds, and as rich as WotN.
As to what I liked: the overall story is fun, even though I don't empathise with evil scum (I'd rather be a hero). Some dialogues are ingenious, but some are childish (I guess there were several writers). There are no bosses (except the final enemy), which I never liked. There's some new beautifull music by Lind Erebros (he's a russian Paul Romero ;).
And it's generally another King's Bounty, which is never enough.
Go get it, and then thumb it down to let the devs/publishers know that they can do better.