After pumping over 100 hours into the game I can give a fairly accurate accessment, sure its early access but I have a strong suspecion this was released into EA literally way too early and it shows.
Constant server problems, although they are addressing that issue but that is besides the point, the game is heavily flawed and those flaws just get worse the deeper you get into the game, later crafting recipes require fairly excessive time devoted to crafting because you need to craft items to craft components to craft into the end product, and with so many different teirs of items compounded by poor storage quality of life issues, doesn't help.
Combat is also extremely bad, no real weapons are in-game because 'tools' serve as your weapons, and you can upgrade them at certain points but be ready to use the same pick axe or wood axe for 20 - 30 hours at a time before you can 'upgrade' to the next tier, fighting is based on attacking weak points but since the flow of combat is way too fast, enemies can easily evade your slow attacks and move significantly faster than you, some enemies can charge at you at 100MPH+ and hit you with a staggering degree of accuracy, even changing direction at insane speeds.
Everything in the game is basically against you, even the elements. You have to constantly use umbrella's to protect you from the sun or rain, otherwise you get nasty debuffs which can absolutely wreck you, in this game STAMINA is king and anything that reduces your stamina makes you vulnerable especially in combat where you can't afford to wildly swing your weapons around as they have stamina costs, and naturally you have to keep eating pretty much constantly, as well as sleep not to mention the maps are pretty large and having to literally run everywhere - it becomes a walking simulator pretty quickly especially once the awe of the graphics wears off and the mundane gameplay loop rears its ugly head.
Then once you reach a major point of the game, Nightingale starts to become more of an MMO with a central hub and parties to explore vaults for more essence, which essentially becomes the focal point of the grind in the end, grinding for essence to trade for crafting schematics to unlock ever increasing tiers so you can upgrade, rarely to you get anything actually 'new' and most of the new stuff is just clothing.
Puzzles are absolutely atrociously designed, with many being broken. The standard puzzle is to find switches AND flip them in the correct order, the problem is they are never easy to find and can go as high at 6+ switches to find and activate, often being hidden and the other type is a equally annoying by killing wisps which briefly will light up a switch...somewhere, and once again often hidden and again its a horrendous design decision that significantly frustrating and 9/10 times unrewarding vs the time investment to solve some of these puzzles, often just 15 - 25 essence rewards, considering the fact you always need 100+ essence to unlock the most basic schematics, it simple isn't worth the time when you could just find other shrines to raid such as might bastilles.
NIghtingale absolutely needs more of everything, more weapons, more biomes, more clothing, more accessories - heck, even things like gems are basically not really used much at all and only useful in some crafting recipes, everything is so out of balance and I can see this getting worse with time, not better - couple with the fact that this is 100% online only, the promise of offline mode is doubtful considering the endgame coop hub is more like a psudeo-mmo, I can't see how this will play out for any offline patches.