So, on monday I finished Deliverance. It took me exactly 200 hours, doing everything and with hardcore mode enabled, according to steam.
TL;DR, I loved the game to bits.

Review:

Before I started my “real” playthrough of Deliverance, I waited for all the patches to be out (1.9.2 being the last) as well as all DLCs. And I upgraded my PC (ryzen, RTX) and used hardcore mode right from the start. List of flaws and bugs I encountered is at the end of the review.

First thing that caught my eye after I started playing (besides a couple of beautiful intros) was how good the gameplay “feel” was of playing and controlling Henry (I play with Xbox One controller). I love the fact that Henry isn’t some detached levitating camera, but an actual character in the world, so I can see my body when looking down, my shoulders or even a bow when looking behind me, my hands when interacting with the world (such as picking arrows from dead enemies or opening doors). It may sound unimportant, but this stuff is not exactly commonplace - of the 3D first person RPGs I played, I can’t think of a single one that had this kind of physicality and presence in the world.

Second immediately noticeable thing is the gorgous graphics. Regardless of it it’s hovels, houses, villages, forests, meadows, creeks, rivers…everything is crafted with an eye for detail and accurate sense of reality. Lightning feels amazingly real and texture quality is universally great. I would even dare say that of today’s games, only Red Dead Redemption 2 has similarly beautiful world. Often I just had to stop and take in the beauty. In concert with the gameplay mechanics, Deliverance is almost like a time machine into 1403 Bohemia. Characters are portrayed also well (especially clothing); where the presentation stumbles is in faces and their animations - particularly eyes during dialogue could stand some improvement to not seem so static.

RPG system. Deliverance takes the best from its competition and mixes it with a dose of common sense and simulation. In practice that means you get better by doing like in a TES game (e.g. shoot deer with a bow —> increase skill at archery and hunting). Added to that is the possibility to select a perk (every skill has its own perk tree) every few levels - just like in Fallout. Some perks are positive, some also have some negatives, but most are useful and enjoyable, or funny (True Slav). They add some spice to the levelling system. Character progression in general is handled very well, at the start Henry is a true village redneck who can’t read or even use sword without it nearly falling out of his hands, but by the end I was able to defeat multiple fullplated enemies simultaneously. It is quite reminiscent of Gothic in that way.

I could waste pages upon pages describing the depth and detail of the gameplay mechanics, so just as a short examples let me write about three:

Drinking. Not only is boozing its own skill with its own perk category, but the way drinking is implemented is both fresh and realistic. At first you drink and feel great…your speaking skill increases, no problem…as you drink more, your view starts shaking a bit, blurs, then you can’t walk straight, and if you get drunk too much, you can fall unconscious. And the next day you feel terrible and your stats are hurt. And if you repeat that too often, you become an alcoholic.

Reading. Because Henry is a village yokel, he can’t read. So in order to read ingame books (and do quests that require it), you have to physically learn to read. Find a scribe and convince him to teach you. Then you sit and read, and as you physically do it, the letters in the books start making sense more and more. And if you sit (even on a toilet), you get a reading bonus. I love this stuff.

Alchemy. To call this a “minigame” is almost an insult. It is simply a beautifully portrayed in-game mixing of various herbs to create potions, their crushing, cooking, combining…no GUI tables like from Excel you would see in other games, but very well portrayed actual thing to do, as it should be. And of course as you practice alchemy, you get better and better at it and unlock new skills related to it.

The world lives by itself, NPCs have their schedules, work during the day, fun in the evening, sleeping at night…I liked the little detail that before people go to sleep, they take off their clothes first. That can be of course used during gameplay.
Or how people greet and comment upon Henry not just by his reputation, but also things like dirt on his clothes.
Deliverance is a truly immersive experience and that almost simulationist aspect - the way tiredness is handled or the need to eat…it all helps the feeling “I am there”. When I was sneaking into a burned out Skalitz and a storm started, I could not help but remember STALKER and its brilliant atmosphere. Deliverance almost feels like a mix of medieval STALKER and Witcher, in a way.

I also have to mention the combat. Combat is not the reason why I play games - I much more enjoy narrative, exploration, dialogues, quests - but it is not completely unimportant. In Deliverance, the combat is designed in a fairly unique way, but it has advantages as well as drawbacks. First the good - the progression works, where at first any enemy is a risk, but by the end you are capable of dispatching even a bit overwhelming odds. Also great is the ability to aim at different body parts, learn new moves, combos, finesse moves like masterstrike or riposte. One issue however is that for the aiming to work, the game uses lock-on, and lock-on can be very unwieldy when facing multiple opponents. It is not always easy to switch and it can be annoying getting hammered from the side because I am locked to a different opponent and cannot look around. Maybe it would be good to let us disable lock-on in mass combat to let us just swing “skyrim style”, but who knows how that would work.
On the other hand, Deliverance is more realistic than most (all?) RPGs and inability to easily kill hordes of enemies fits quite well here. When I go clear a camp full of cumans, it makes sense to first thin out their numbers with a bow (perhaps with poisoned arrows as well) and then try to take on the rest (and use hammer if they have plate armor). Trying to play more intelligently than just rushing in the middle of the enemy pack and dance/slash, Witcher-style.

Quests. In a game full of innovative approach to design, quests are perhaps the most interesting. Not only are they generally well written, allow for various different ways of completion and use the game mechanics to their fullest, but the game also pleasantly implements time. So quests where it makes sense can be urgent and have a hidden time limit, and if Henry dawdles, things can happen without him. But there is no game over, game continues and you just have to do things differently and face the consequence. Henry is a great protagonist, I had no issue emphatizing with him, although it is true the dialogue and story is written more for Henry a Good Person rather than Henry a Psychopath. No problem with me, I don’t like killing innocents and stealing from them. As far as quests go, I won’t spoil any details, but get ready to investigate various crimes, searching for heretics, help with wedding preparations, trying to cure a village hit by a plague, infiltration of a monastery (particularly amazing and ambitious quest) and many others.
Quests are at similar quality as Witcher games, from player agency standpoint are possibly even ahead of them, although unlike Witchers, Deliverance has one set ending. By the way, the DLCs are absolute must for a complete experience. Not only do they add extra functionality (a dog companion, village rebuilding) but Amorous Adventures and Woman’s Lot contain some truly outstanding quests. One is comedy, the other is tragedy, but both recommended.
It is true that Deliverance’s ending leaves door (or a gate) open to a sequel, but it’s so meaty and satisfying that I didn’t mind, with its beautiful outro and epilogue as well as awesome orchestral metal song in the credits. That brought back memories of Mafia 1 and its Lake of Fire song in credits - also seemingly unfitting, but actually being a perfect last note.

For completion’s sake, I will list the bugs and things to improve into a sequel. I assume people at Warhorse are aware of all this - some stuff is simply limitation of the technology or lack of budget.
First, the bugs:

I fell into a ground once in a forest (hunting rabbits, rabbit disappeared so I followed him and fell right there with him), had to reload
inability to zoom map in Rattay (fixed itself in few hours)
during dialogue with Štepánka at Talmberk, camera stared into a wall instead of Henry
from time to time, NPCs can walk through another NPC
Kuno (character from DLC Band of Bastards) was nowhere to be found and I could not continue the quest, reload fixed it
once, Henry did a T-Pose in the inventory (fixed by game restart)
two crashes to windows (both caused by too small swap file in windows - after I increased it, no crash ever again)

Things to improve:

I understand that Warhorse does not have Rockstar’s resorces, but I still hope sequel will improve on animations, both facial ones and standard ones (barmaid looks a bit too robotic)
the amazing graphics is hurt but LoDs (swapping model complexity depending on player movement). It is visible particularly during fast horse rides
indestructible and impassable bushes. I get that some bushes in real world are nigh inpenetrable, but it is still a bit ridiculous for my great, strong horse Sleipnir to get stumped by a small bush
sometimes (fortunately rarely) the text in quest journal did not accurately reflect what I did, and some dialogues did not flow completely logically
clothes clipping can be visible from time to time

One last note about the hardcode mode. I wholeheartedly recommend playing with it. The game may be harder (I have no comparison, never played base difficulty), but the single lone fact that there is no Henry icon on the map - no GPS - makes Deliverance even more amazingly immersive experience. Having to really look around, pay attention to the surrounding landmarks, navigate by rivers, buildings, sun position…brilliant. Deliverance is probably the first game in forever where I genuinely got lost in the woods. Some may find this annoying, but I loved it.

In summary: Kingdom Come: Deliverance is, together with Red Dead Redemption 2 and Witcher 3, my favourite game of this generation, and probably of all time. If you have good PC, patience and ability to appreciate something fresh and immersive, you will very likely love it.