These are developer comments from the Kickstarter page's comment section, where they have answered various questions from backers. There are obviously more, but I think these are some of the more informative ones, and I figured it was nice to get them collected somewhere as they are 'lost' in the comments section over there.

I may edit and expand this in due time.

Have just glanced at it so far, but here you can read more about (GOG's forum sucks so I gave up on making inline links):
Classes
Races
Spell system


XP
Every combat gives XP in Black Geyser. And a goblin gives the same amount of XP at the end of game as at the beginning. Classic, Baldur's Gate inspired mechanics.

Custom portraits and XP caps
You can certainly important custom portraits and voicesets. There is no XP cap planned, thanks to the clear system of the game (e.g. no senseless respawns). Yes, dialog checks will be made, and there is an advanced way to developers (content creators) to define intelligent dialogs. The reply options you receive and the text & decisions of the NPC speaker can depend on a number of things, these are basically scriptable by the developer.

Watcher's Keep type area?
The functioning of Amanuel's estate is similar to Watcher's Keep in some ways but not similar in other ways. Watcher's Keep and other dungeons in crowdfunded RPGs are depth-oriented, sometimes going very deep as subterranean areas. While Amanuel's estate also has underground areas (with creatures who do not welcome you), it is primarily a horizontal estate in terms of the stretch goal.

Creatures
A few creatures that have not been mentioned anywhere yet:
* Fire Salamander
* Tree Mist
* Demonic Tree Mist (more dangerous version of Tree Myst)
* Coral Fiend (typical to sea shore areas)
* Lake Zombie
* Jotunn (rare creature, shouldn't be confused with their "smaller" brothers, Frost Giants).

Based on additional money (stretch goal-like monsters): Hydra, Zodiac Fiend, Cyclops.

Playtime and DLC
The total playtime can be up to 80 hours. Minimum playtime depends on the player too, some people can finish Baldur's Gate within hours or less. With DLC, we take the old-school approach (expansions). We plan at least 2 major DLCs.

Inventory and resting mechanic
inventory is both slot- and weight-restricted, and there is no movement seed penalty as long as the carried weight is within the allowed range.

There are two types of resting in Black Geyser: Couriers of Darkness: short rest (campfire button) and long rest/sleep (tent button). Short rest also regenerates HP, but spells are not re-memorized into their slots. Its advantage over long rest is that you can do it anywhere, even in towns/cities. Long rest is possible only in the wilderness and outskirts of cities, so when you are in a town or city center, you should find an inn.

Templars can cast spells, but they certainly don't have as many options as Clerics.

Class restrictions (sort of)
Class-specific skills cannot be learnt by other classes. Only rogues (e.g. Thieves, Swindlers) can advance in rogue skills such as Steal or Plant Item. Universal skills, on the other hand, are available to all classes (but not all classes can reach the maximum):
* Bargain and Persuasion
* Learning and Research
* Brewing and Drying

Weapon skills/types
You asked about weapon specializations. There are 9 weapon skills:
* Bows and Arrows
* Slings and Fustibals
* Throwing
* War Clubs and Hammers
* Greatswords and Long Swords
* Short Swords and Daggers
* Battle Axes
* Spears and Halberds
* Rods and Staves

Just letting you know, there is already a 4-page (as of this post) thread about this game. Check it out.

https://www.gog.com/forum/general/the_next_crpg_hit/page1

True but this thread has the game's name in the title :D

I'm super skeptical of two things I see common to Kickstarters:

a) very low funding goal. $60k won't buy you much of a game, let alone after paying out the rewards.
b) core gameplay elements listed as "Stretch goals".

The low goal worried me too, which is why I asked them about it, or rather if they could say more about the other investors and the total budget. They didn't say much, which was half-expected (they may not be allowed). But they have written a bit about it on the Kickstarter page. Would be nice to know more about it, however. But it's pretty clear they have worked on the game for a few years already, probably with a pretty sizeable budget. The gameplay videos look good, with art assets and such. Maybe these private investors are of a "we will fund you €10 for every €1 raised" in the Kickstarter or something to that effect. Hard to know, but they must have got most of the funding via other means, or worked their ass off for nothing/little.

I'm certainly not their spokesperson, but did read up a good deal before deciding to back it (early bird for now), so a little info I saw about this:

Years of hard work and a lot of money have been invested into Black Geyser: Couriers of Darkness. As a new studio specializing in role-playing games, we are grateful to our investors who have funded development so far.

A successful Kickstarter campaign is now required, a proof of interest to our investors that will secure their final round of funds. These funds, combined with the money raised on Kickstarter, will ensure the completion of Black Geyser: Couriers of Darkness.

As large as the gaming industry is, in some respects, it's very much a tight-knit community. Word got out pretty quick what we've been up to, and we've already received inquiries from publishers interested in Black Geyser: Couriers of Darkness. We concluded that involving a game publisher for funding the completion of the game would tie our hands, limit our creative freedom and restrict our ability to customize the game based on your feedback. On the contrary, a successful Kickstarter lets us keep our freedom and directly involve you in the project.

While our private investors cannot act as a substitute for a successful Kickstarter, they have pledged significant funds if our Kickstarter campaign is successful. They have also agreed to help us handle any budget risks and unexpected events during the development.

The game has now been funded, which I think is good news (not the GOG variant).

Getting to the 100k stretch goal may prove tricky, but it's possible they make it.

People love their crpgs.There's another big one being funded.
Pathfinder: Kingmaker, set for later this year. Everyone's favortie Chris Avellone is writing for it too.
If i end up getting PoE 1 and 2, i don't know if i'll want another crpg for a long time though

Update should roll in couple of hours or less.

Why is it that when I read „Our upcoming KS update will hopefully clarify all open questions.“ I have to think „Epic exklusive“? ;)
No, I did not give any money to this project, so I don‘t care which way they teally go.

They said update should be in next few minutes, it was not. Scammers.

EDIT: but it's now published, so....

That update doesn't exactly fill me with confidence, some nice artwork aside (although those ears seem rather erhm impractical). Although they say otherwise, it kinda looks like the investor they talk about are getting cold feet. Or perhaps are concerned about lack of progress and don't want to fork out until they see more concrete progress / a realistic finish.

All in all I can only reiterate that I am glad I pulled out. If the game is ever released and worth playing, I can always jump back in, although for a higher price. But this one had more red flags than a military parade in the Soviet Union.

The game looks somewhat good, from the pic/info posted....definitely worth a watch, imo.

Sidenote: The guy in that pic you posted looks a bit derpy. Methinks he's been sniffing the fumes from his potions a bit too much.

20 minutes of new gameplay:
https://www.youtube.com/watch?v=AZPeiO7s5Zo

Late backing is still available too:
http://www.blackgeyser.com/backerportal#rewards

The most recent Kickstarter update indicated they were pushing the beta back until November and the live game until April 2020 after some hurdles with a funder and benchmarks that got resolved favorably. Looking forward to Black Geyser despite the delay, which I suspect is a normal thing with video game development.