Well, despite the hard situation I am in, I will try to give a cohesive overview of changes that I feel are very, very transformative for the gameplay flow as a whole;
The first thing I noticed is that some traits got changed, like toxic power no longer giving physical damage boost, which also made it cheaper, so its a change that can be either good or bad depending on your previous old tactics. Oh and hidden power trait finally got fixed for the fact that the shapeshifter was able to apply true damage modifier on everyone(but that trait still remains a powerful option especially for 1 difficulty modifier).
But that was just traits that I did observe, now for something much more impactful - the arena ranked matches are no longer action cost free as before, now you have to either take training option, or request an arena match, which means 2 extra ranked matches at best per day rather than previous infinite that lasted as long you could empty your characters/money at. Makes money and experience acquisition via arena combat less powerful, but no less important.
The new art is nice, though bugs on the fire dragon character portrait art related to clothing options. The character changes however on some, like the fire demons replacing their damage skill with a fire berserk skill that has both offensive and defensive applications is a good touch for gameplay variety, especially with the new affinity system I would like to discuss.
The new affinity system is basically have characters of various affinities, up to 5 in each category, that allows for rather powerful impacts in combat, like total immunity to slow effect from enemies or dealing double damage to enemies with no mana left, and so on. It makes gameplay more varied, because now the enemies can benefit from them as well. And the essences for selecting starters gives more thinking of a choice, either specialty at one species, or powerful effects that will help overall, like dual beast essence giving +1 to vision, which combined with scout profession, allows to reach the new highest possible vision, 7 hexagons.
By far, my favorite change however was making item abilities from limited across all battles(consumables are unchanged)into per battle, which made otherwise too great to use items expect in extreme situations like spectral sword active ability into pretty much a never a bad combat tactic, and making otherwise useless late-game item abilities like fire swords into a one that is worth considering, and giving items that only had passives like lifestealer have abilities too. Artifacts and certain special items are still unchanged though, but generally their power makes up for it. And the new items added do really add the changes to combat, like a stone sword that deals extra true damage if the target resists the damage element, becoming a spectral sword lite for strength characters against enemies with resistances, like crystal towards most damage types, and so on for others. And certain consumables got buffed, like health potions recovering 15 instead of 10 health, probably because of fact you would rather use a character with a healing skill using a mana potion to recover much more health for less cost.
Succubus species characters(not all of them, but I hope as many as possible, especially uniques that do not have it)have a special passive that doubles their skill experience, which is great, since training brothel workers while not exactly bad, felt only worthwhile for characters with high beauty in the first place/quests, not for actual specialists that now we have. Though beauty wise, they are not the highest, the fact you can train them much faster can make a difference for getting workers as quickly as possible, or especially quest targets that require trained characters.
The new difficulty modifier, casual is a rather strange one - it doesn't make things harder or easier as it supposed to be, but it gives very random characters with random stats/genes, which means you can get a basic character with may or may be not solid stat-line and traits, or a powerful, rare character with again, may or may be not powerful genes and traits, which in terms of what you can get, includes characters that are hard to find like seals, the special character that you get when you have 5 of them, and so on.
In fact, the casual modifier is arguably the most useful one if you want to get characters that are hard to get, and its penalty, reduced recruitment chance only applies to humanoids; mind control still gets them without issues, overworld rescue events/unique characters are the same and creatures have the same chance of getting caught as normal, meaning you will simply rely more on creatures/unique characters until you get the mind control skill. The tavern though, becomes effectively too expensive to even use, unless you rake in the money at later stages of the game and only buy high tier hirelings/rare characters. But considering that the tavern has limits to what characters you can get compared to random output that has less of it, I find it less of an issue, but more of annoyance.
Alongside those, I found that shapeshifter can adopt themselves a trait they learned, naturally it finally allows getting the symbiotic trait being unlocked, since you need more than 5 characters with it in the first place, while allowing you to apply a trait that either makes you even more powerful like ancient power, or anything that you may use as a protection, like ethereal. And you cannot readopt till another transformation, because using evolution potions would make it extremely overpowered, so its just powerful. Not that it doesn't stop you from using mutagen in the first place, but its way too random.
But that's one thing; another that can be used in place of trait adoption is ability to change/add skills for characters, shapeshifter can apply it to any character, while others to what they summon, like slimes and seedlings. Not an easy choice when they have an option to add a trait, but becomes one if they are full of traits in the first place. Before that change there's a shapeshifter perk that did that, but it uses your skill pool of skills in order to apply them, nor couldn't change skills that are on the character already, meaning if you learn it now, you can use your own skills in addition of what the character normally gets/their species.
Overall, I am very pleased with such gameplay changes giving a well needed change for the better, since there were not enough elemental weapons, nor enough variety of them, since generally you want to use equipment with powerful passive effects, and there were only a few. Now there's much more, alongside armor with abilities, all going to find their favorites. I can only hope for new surprises that gives new gameplay options that reward creative applications of what you have. I still have to yet to get all of the new content, but I hope will do.