So is this a spiritual successor to Darklands?

Simply put, yes, but has many things superior even to games built upon Infinity engine that picked my interest. Well, they didn't joking about that hardcore and open world, my party was killed by simple wolf and I'm not frustrated, only motivated to try something differently. ;-)

I'll probably pick it up then, but now I'm curious as to what they've done that's superior to the originals.

Graphics looks like enhanced Avernum (especially underground and caves), skills works like Divine Divinity and battle with active pause feels like Baldurs Gate with actual economy and character development like Icewind Dale.

I'm not that far in story but what I see so far is balance of dialogues and texts in books, letters, hints. Of course you can write everything to your journal but you won't get lost if not. Not sure about interaction between
party members but they have certain story, dialogues and depth, of course only npc ones, the ones you create like Icewind Dale not. You can turn companions into possessed slaves but that will kill any personality in them.

It's a 'spiritual successor' to Darklands or Baldur's Gate. To be honest, though, it plays to me more like BG with Darklands graphics. The magic/class system is novel, compared to other RPGs, IMHO.

What I'd hoped for a 'Darklands successor' would be a game in Europe (this is a fantasy world), with low-magic (can't say, but it seems more like a high-magic world), with regular-people characters (we're playing a god's avatar, transformed to a mortal form, and need to find out why), with separate gameplay/UI for world map and combat map (haven't seen any yet).

The graphics are generally drab, but they do have their charm. The UI is pretty difficult to understand, and has lots of buttons which are hard to find, and hard to know what they do (tooltips exist, but are pretty limited by modern game standards).

Overall I'm pretty disappointed, but I'm still giving it a shot. Haven't had much chance to play, not well enough to have a final verdict.

Definitely not a spiritual successor to Darklands, and anyone who claims otherwise isn't familiar with Darklands.

It has a similar graphical style, the world is dark and loosely based on Eastern European folklore. That's about where the similarities end. Mechanically it is a very, very different game.

I'd say it's much closer to Baldur's Gate.

It is graphically inspired completely by Darklands. Gameplay-wise, it's a more hardcore version of Baldur's Gate than anything else. It's an impressive project any way you slice it, from what I understand done by a 2-person husband and wife team. In it's own way it's as impressive as any of the other games we've seen in this recent CRPG revival.