Appaling optimization aside, gameplay and story are great and it's a shame this game has been so overlooked (as is the style with Square Enix published games).
Skip the DLC though, if you don't have a big passion for grinding and character building.

TL;DR: This is the best Niohlike to play with your friends if you are actually into fighting strong enemies. It is also the best Niohlike in terms of build options. The game is basically just about boss fights, everything else is pretty much filler. Below you will find a short distinction between story and endgame and a somewhat longer delve into how I recommend playing this game.

Minor spoiler warning from here on out, (difficulties and abilities, but nothing concerning the story)

<spoiler>SOPFFO is a fantastic game in its own right, but needs to be played the right way. This is a game with split opinions on it, due to it being split into two parts which appeal to different kinds of gamers:

1st part is its story mode (playing through the story, everything before unlocking chaos mode)
2nd part being the "endgame" (All difficulties and their addtional content. Chaos -> Bahamut -> Gilgamesh -> Lufenian)

The story part of this game can appeal to any kind of gamer who just wants to play this game and basically beat it. There are a lot of people enjoying this game just for that. For people enjoying fights this is just the tutorial. Experienced Nioh/Soulslike Players will breeze through this, especially when playing this in multiplayer. Be aware that this game does not really have all that much story. It is still a great game to face some nice bosses, even if you are playing casually, but if you are looking for an epic tale of a final fantasy game - this is not it.

If you are here for the second part: Beating up Badass Bosses with difficult patterns that will kill you including your homies over and over again - then this is the perfect game for you. SOPFFO does this better than any other Nioh or Soulslike game. It is the only game where you will have actually difficult fights which dont reduce down to just mashing enemies down (like in nioh). You will also need to make a working build later on in the game, which will consume dozens of hours to complete over the whole game (which is fun). Take the story as a tutorial and get used to the different weapons and classes and pick your favorites. Going on from Chaos difficulty you will need to actually make a working build to not get beaten to a pulp. I Recommend taking one of the guides to somewhat rush through all difficulties. This is actually the game. There is a lot content you will go through doing it this way. I played this game a total of over 100h this way.

This boils down to:
* Clear the story
* Take some time beating the solo fights at the end of the story :) They will Tear you apart for a whole day :) -> Unlock Chaos difficutly
* Up to Level 300 ASAP and go for Bahamut ASAP. There is need to linger on Chaos Difficulty (you can though and unlock class upgrades from missions if you want, but you can also do that on higher difficulties)
* Beat Bahamut Difficulty
* Gear Up - I don't remember when you actually need to first gear up. You might need some stuff to beat bahamut already.
* Unlock Gilgamesh Difficulty -> Do the Gilgamesh Labyrinth until you unlock Lufenian difficulty
* Clear anything you want to do on Lufenian. Definitely gear up and make a build on lufenian or while doing lab. Pump up the difficulty with Bahamut trials (the level+ thing)

The experience is a bit scattered and bit of "build your own content", but if you are fine with that this game can deliver some of the best time you will have with your friends if you are into hardcore fights and building characters.


Some General hints:
* There are guides for how to advance to Lufenian difficulty which describe what I summarized above in even more detail. I highly recommend picking one of those up
* Once you are through Story mode: Pick up the Spreadsheet. There is a Google Doc online with all kinds of informations about types of attackes, their strength, element, stat bonuses of classes, summons, etc. This is strongly recommended to use for endgame when you start making real builds
* There is an active Discord for SOPFFO at the time of this review. I got someone to open a high level (150ish) Gilgamesh Lab for me so i could copy his level for example.
* This game has HP damage and Break damage. You only need either of them to kill an enemy. Distribuing your multiplayer party across both options is senseless. I recommend settling on break damage as it is a lot more universally doable for most builds.

Some Further Restrictions I recommend for the endgame:
* Before going into these note: Play the game how you want. It is completely fine to just use everything the game has to offer if that is more to your liking. I personally think some options take away from the game though.
* Do not use Knight 400% - This is probably the easiest way to generate an insane amount of defense if you know how to build it. Just never use it and you will still have to survive. You will know what this later on in the game.
* Stay melee - The game has Options to play Ranged. I prefer Everyone to always need to watch his offense as well as his defense, which makes Soulslikes so interesting. By having a party and some people being ranged you can play more of a holy trinity (tank / dd / healer). Just note that this strongly lowers the overall difficulty. If you like that though, you do you, that's obviously totally fine.
* Do not use taunt/invis: The game also offers skill to either draw more or less aggro from enemies. Same reasoning as above. Do it if you like, but don't if you are looking for real, authentic challenges
* Do not use Reincarnate: Reincarnate is a spell of a white mage specialization that revives a fallen comrade as well as just picking him up the next time he dies. Guess what: This is reaaaaally good. Having a support character otherwise is fine.
* Do not use Dimension bringer: After Clearing The Gilgo Lab you will get access to Dimension bringer. This is an alternate Form of Lightbringer which completely slows time around enemies during its uptime. Well, slowing down time meaning completely stunning the enemy, basically. You can spam this in the right setup. I recommend avoiding this at all costs.
* Ninja Utsusemi - This makes you evade the next three hits your character would take. Bit too of a defensive layer in a multiplayer scenario for my taste. I recommend not using that as there are attack spams in the game with a lot of iframes (looking at you, daggers). Especially braindead of a combination when used together with High HP Sentinel.
* Sentinel - Sentinel is bit of a tough one. Sentinel is a skill that gives you a shield based on your max HP. Thing is: you can have a second class with as much max HP as possible, cast sentinel and switch to your glass cannon main. Sentinel also prevents Stagger. In most phases of the game this can give you a bit too much of tankyness for my personal liking. Generally i would propose to just enable sentinel on your main class, but in the latest stages of the game (lufenian difficulty) lifting that restriction is fine and we used this as our main defensive layer.
* Do not use large screen clutters - This probably mainly applies to Sage. Using Ultima is the ultimate screen clutters turning your mates screen into a black exploding mess. Not fun in a game where reaction is everything. I recommend not using sage... or playing sage without ultima if that is an option to you
</spoiler>

Took a while for the combat systems to click with me, but once they did I was having a lot of fun. I could do without all the number goes up gear management though, like every 10 minutes you get some gear that's better than what you already have and I just don't care, I don't wanna ♥♥♥♥ around in the menus, I wanna kill chaos.