3/10.

This is probably the worst One Piece game that exists on PC.

The frame rate is capped at 30 and the frame time has spikes in it, the frame rate can dropped out of nowhere, this can be observed with RTSS (Rivatuner Statistics Server).
It can't be minimized in background unless you play in windowed mode. Trying to ALT+TAB while in full screen mode will change the mode to windowed.
The mode Pirate Flag Battle has been closed since 30 October 2020, due to this closing several titles and emblems can't be obtained anymore since the mode was always online.
Doesn't support resolutions higher than 1080p.
Buying the GOLD Edition does not give all the DLCs, there's one DLC Golden Luffy that was only available on Bandai Namco Store and the codes for it expired.

Several titles and emblems are tied to Online mode requiring to battle with each character 30 times, that's insane.
4 Achievements are tied to this mode, good luck finding someone that wants to play this dead game.

Story can be completed in 2-3 hours and maybe 4-5 with extra chapters. Some extra chapters have insane requirements.
There's one arc, the Marineford and it's not like in the anime, do you remember when Whitebeard screamed "One Piece is real" and everybody was silent and shocked? Well this isn't here. How about Luffy when he screamed "STOP" and several marines were dropping, this isn't here either, instead they put only 2 marines dropping. I can name more, but you get the point.
We can see Koby, Squard and Pacifista fully modeled and you can't play with them at all.
There're 4 episodes and they repeat cutscenes and battles. They also show images from anime while the narrator is speaking, some are again repeated.

At first I thought I can't play 1 vs 1, but later I found why, the default mode for selecting characters is not empty to select a character, it's random and you need to remove it if you want to do any battle you want such as 1 vs 3.
This must be done every single time you enter in Free Battle mode.
Who put the random as default instead of an empty space must be truly special in this world, please live your life under the planet.
There's no AI vs AI like in other games. The only way to watch AI vs AI is if you're AFK in Title Screen for 30 seconds.

There're 44 real characters from 71 and only 4 of them are from DLCs. Costumes are not treated like costumes, same movements with different look, they treat them like other characters or versions of them.
Let's take for example Jimbe, the default is him 2 years ago, but his costume that can be equipped it's him today and that's a different character. For Nami (Swimsuit) the game treats her as a version of herself, not as a costume to be equipped. Now something different, Smoker is treated as 2 characters, the one from today and himself 2 years ago. This doesn't make any sense.
All characters have voices that can be earned in game just by matching them with allies or enemies, you don't know how to match them at all. There's no indication, nothing, it's a waste of time. Pacifista also have voice lines even if he's not playable, but in order to unlock them you need to have Admiral For Admiral unlocked at Wanted List from WANTED Versus. You're obligated to play this mode otherwise you'll never unlock them, it's unbelievable on how much this game sucks.
There's no explanation on why leveling characters exists. When all characters level up, be ready to skip for over 1 minute cause there's no "skip all" button.
In Title Screen and in Main Menu characters appear in a slideshow, but Garp, Lucci, Caesar and Tesoro do not appear at all since they're DLC and don't have a normal version of themselfs. Lazy developers, how hard it is to include 4 characters.

At some point in story the tutorial showed wrong indications on how to perform a move.
I found even a reddit post about it, says everything about this game.
The tutorial teaches you only the basic, if you want to learn more you'll need to go to WANTED Versus and train.
Trying the setting Simple Controls may help some people, but it doesn't let you to do any special attacks that you want, it does random attacks by combining them, the game plays for you.

In WANTED Versus mode you earn Beli and Keyword Logs for Collection.
They either forgot or it's intentional in this mode to not have a retry battle option, something the story has, so you have to let the AI beat you to retry it, another waste of time.

For Keyword Logs they show images for certain characters, then they stop, I guess to insert some images for all logs was too hard.
Play Hints show only the basic characters costume or their normal version, but in loading screens hints can appear with version of characters such as Robin (Swimsuit) instead of the normal one. I can't find a reason of not including the alternate versions to be seen here because the art is actually good.

AI it's how you expected it to be, unbalanced, spamming moves especially the range ones, sometime it may get stuck moving in one direction trying to leave the map.
Doesn't matter if in Free Battle the strength is 1 from 7, the same things can happen.

It's a waste of time, there's no fun in it, it was made for a quick cash grab, Bandai Namco didn't care like they always do.
One Piece fans are delusional thinking this game is actually good. Sold poorly, but at least beat Concord in players numbers :)

Burning Blood looks great, masterpiece and nails the flashy style of One Piece.

The visuals and animations are incredible. Every punch, slash, and Devil Fruit ability explodes with color and energy. For a few fights, it feels amazing but then you realize that’s kind of it. The combat system is flashy but shallow, with limited depth and a lot of repetition once the novelty wears off. Also FMV cutscenes can audio desync and the frame rate is capped at 30 and the frame time has spikes in it, the frame rate can dropped out of nowhere.
THIS game is so fckin expensive -_-