Second 'Like A Dragon' game I've played.
I feel, so far, these games aren't extremely polished on the gameplay side of things. If we're only discussing combat, that is. For context, I played this start to end on "Legend" difficulty, the highest feasible difficulty ('Ishin' mode explicitly states that it should only be attempted on new game plus). I did 90% of substories, all the dungeons, and did a looot of crafting. I didn't do much of the arena, why? Well, one fight had a foe shoot me with incidenary bullets that literally stunned-lock me to death. Sadly that wasn't the only time I loss more then half of my health from being trapped in a inescapable combo. I'm fine being punished for not dodging the initial hit of a combo, but the amount of total combined damage doesn't really feel fair with how quickly some of these enemies swing their swords. Am I saying this game is too hard on Legend mode? Not really. If anything, this game goes repeatedly back and forth with it being too punishing, and yourself being utterly unstoppable. You can craft and buy some seriously disgusting weapons, like a cannon that will literally infinite combo most foes and some bosses, or the Vortex pistol which shoots so fast that it shreds health pools in seconds. Then there's the trooper system that are special attacks, and if you have the tiger trooper (as in a literal tiger) then that's near-guranteed instakill on a single enemy. Did I mention that some troopers are real content creators (which are free DLC)? One of which is a Vtuber. No, I'm not going to spoil who.
Of course there's a lot to do beyond shoving swords up a ronin's ass. You got karaoke, dancing, fishing, gambling, farming, pet managing, cards, shogi, cooking, and the bane of my existence, chicken races. What's wrong with that last one? It's easily the best way to make money in the entire game, but its of course luck-based. And every attempt takes an agonizingly long time. And sometimes you get those ""fun"" moments where ten times in a row the chicken with the highest possible chances of winning just never wins. Literally gone for half an hour before winning once, but the payout is honestly worth it.
Substories are very frequent compared to 7, which my first Like A Dragon game. Wasn't a fan how a ton of them required coming and leaving so many times. You'd visit a friend, give them a item, walk away, then come back. This happens an absurd amount of times. They do provide a lot of cute, and funny side stories so they're at least worth it.
It's funny how many issues I have with this game, but it's hard to hate. It has some great set-pieces, a roller-coaster of a plot, excellent sound design with stellar choreography in cutscenes and combat, a ton of stuff to do beyond the main story, and honestly quite a lot of heart. You know you've done good when I've invested so much time in your RPG system to want to grind for rare materials, namely to see the great weapon designs. Not necessarily for stat ups. And while not my favorite, the music did its job very well across the board.
That aside, you can spin around like a madman with your katana and your rapid-fire pistol as you carve a path of death, then summon a bear for good measure. That should be enough to convince you one way or another.

If I made a game, and I say this with zero game dev experience, it'd probably be something like this. Not necessarily my "dream game", but this has so, SO much stuff I'd put into a game.
A class system with that allows for a lot of creative synergy? Check. A huge world that has tons of hidden bosses and secrets? Yep. Challenging turn based gameplay where even the non-boss encounter requires you to give it your all? Got that. A story that... actually the story really isn't there. If a normal RPG is about 45% story and 55% gameplay, Crystal Project is closer to... 2% story, 98% gameplay. For context, my final game time on Steam was just under 40 hours, and there were several optional areas and superbosses that I haven't seen yet, plus a chocobo-like breeding game.
If you want to know if you'll like this game, then you'll have to love turned-based battles and exploration.
Let me stress this point, exploration is a huge component. Nearly as important as the the battle system. It starts fairly simple, but then you start to get mounts that allow you to reach areas previously unreachable. Still sounds standard... until you realize the game's world is all interconnected. It's an entire open world game made by one dev. Its kinda crazy. Not one area takes place in some separate dimension, such as entering a world map in other RPGs. You can fall off a giant cliff and plummet all the way into the ocean. And if you can swim by that point in the game, you can seamlessly go underwater and find treasure and dangerous foes in the ocean's depths.
Speaking of foes, this game is fairly tough all things consider. While it is possible in some parts of the game, most of the time grinding levels isn't an immediate "I win" tactic for the more difficult encounters. It certainly helps, but if you do a lot of side content then you'll reach max level quickly, and will still be struggling if you made your party poorly. The game does have your back in many ways. Your stat-increases are dependent on the class your character was when they level up, but you can rollback and redistribute them if you aren't satisfy with your build. The game is very transparent about its mechanics, like the exact calculations it uses when calculating damage, what party member an enemy will attack next turn; even the exact damage values, crit chance & crit damage, and accuracy percentage for every attack you do is clear as day.
I played on my new Steam Deck and it was the one game that didn't drain my Deck in 30 minutes, which was nice to say the least. Have had some notable graphical hiccups, namely with the world taking a bit too long to load after fast traveling or moving at high speeds. I had no issues with this personally, but a lot of music and game assets are used from many royalty-free dev sites. I felt it was done well enough that I didn't notice during my playtime, plus it does rightfully credit where they came from so it by no means tries to hide it. Only big issue I had was that I would've like a little nudge towards some of the more interesting discoveries in this game. This game world is massive and it can be exciting but also very overwhelming. I had to look at a guide (which there are so few of) more then once to get at least a vague direction for points of interest, some of which are very easy to miss.

If world building and story is what you love about RPGs, then this is ain't for you sadly. Me though, this was just sweet dopamine in my brain the whole way through.
Did I mention this game also has an in-depth randomizer? Like random bosses, enemies, class locations, items, and more? This'll keep me busy that's for sure.