This game takes the best things about exploration and job systems in RPGs and puts them together in a way that feels so, so right. The game has a lot of heart, has a wide, charming world and feels good to experiment in. Making up a good party with the many character customization options available (job combinations, unlocked passive effects from jobs, modifiable stat growths, equipment) feels really rewarding, too.

It can be a bit unbalanced at times, but jobs all have their chance in the spotlight in a well-composed party. Unfortunately, the story is pretty lacking, as the emphasis of the game is very much on gameplay and exploration; still, Crystal Project executes those so well. Highly recommend :)

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.

Wow, yeah, this is pretty good!

What I Liked

-The exploration
Big honkin' ol' voxel world, and you can platform two (2) boxes high and three (3) boxes wide, which means that each time you get a new method of traversal it feels like a huge increase to your explorative capabilities. If you like exploring off in random corners and seeing what weird shit's there, this has a lot of that. The warp point limit (and I used the additional home points assist option) feels incredibly restrictive at first in a way that makes you appreciative of the world design later when it's no longer an issue.

Like, remember how in Dark Souls, you couldn't warp for the first half of the game, and that added a huge amount of texture to simply traversing to your next destination, and more importantly, back home after a major trip? Like, finding the bonfire in the bottom of Blighttown is a blessing because it's finally a bonfire and then a curse because now you're stuck in Blighttown? It's a little like that.

-The class system, most of the time
FF-style job system, right? If it ain't broke don't fix it. You get a main class with an active ability and passive bonuses and a sub-class's active ability. Support abilities are lumped into one big pool and each has a point cost, so there's some decent configuring to be had. I stuck with a tanky physical boy, a dex/agility DPS, an offensive spellcaster, and a healing/support caster, and it worked out most of the time.

-The battle system
Yum yum, give me that transparent turn order and damage numbers. I didn't get up to the kind of shenanigans I did in Bravely Default (Hasten World + Jump) but I had a few boss fights that came right down to the wire in a really satisfying way. I am always a fiend for Damage Over Time abilities and there are like three different kinds in this game fuck yeah.

-Assist options
No missable items is a nice one; there's a Lost 'n' Found vendor in the main city who sells all of the boss steal items and anything that was in a chest that wouldn't fit in your inventory. You can talk to an NPC and respec your level growths at any time, which is great for the kinds of people who would step on that one trap space in Final Fantasy Tactics that lowered your level, but you would do it with a crappy job with bad stat growths, so that you could level up again later with a higher tier job with better stat growths, thus achieving a net gain in stats. But I'm sure nobody would do this.

I turned on the multiple home points thing immediately, but in retrospect I might not have needed to. There are ways to configure the battle difficulty and to win minigames instantly and such (I will never race another Quintar again as long as I live). I also fiddled with the ones that let me configure EXP/Gold/Job Points rewards, which sort of leads me into...

What I Didn't Like

-The game is somewhat judgemental about you using the assist options
Once you turn them on, you can't turn them off, and each puts a permanent mark of shame on your save file. This is ridiculous. Just let me have the sliders set to 100% normally and let me move them up or down as I see fit, alright? Have a little trust.

-Long term progression is unreasonably tedious on Normal mode without using assist options (IMO)
Okay, so like, with this kind of JRPG, non-boss encounters are all about resource attrition, right? You don't want to use up all your healing items before you get to a boss, because you want to be as close to full power as you can. But you also need to fight them to get strong enough to fight the boss, so you can't just skip them all. It's the push and pull.

Encounters in this game will fuck you up. I assume I was pretty much on level curve, and I would often end bog-standard encounters with one or more party members downed or at low health. This is not bad in itself, but the game also has restrictive limits on how many restorative items you can carry, gold is fairly scarce, and equipment is expensive. By the time I was halfway-ish through the game, I was starting to dread reaching big new areas because I knew it would be a huge uphill climb.

Then I turned gold earned up to like, 150%? of normal. Enough to actually afford potions and at least one piece of the next equipment tier for the whole party. Suddenly everything got way more manageable, while staying tough.

-The map system
Specifically, the way it won't even show you where you are in the void if you don't have the map for that location. Look, fine, don't give me the minimap, but I deserve to know my relative location on the world map.

What I'm Ambivalent About

-The lack of story
It's not that there isn't a story, or that what's there doesn't do a decent job, but I could go for a little more meat here. For what it is, it's perfectly adequate, I guess. Just like, in Breath of the Wild or Souls/Elden Ring, the big-name "explore off in weird corners and see what shit's there" games, you often find things that tie back into the main plot and backstory and such or add flavor. In Crystal Project you might also find a sick sword, but it won't have a cool, evocative description that deepens your understanding of the world and its inhabitants. And that's fine, but I sorta wish wish it did, you know?

The only real exceptions to this I think are the final boss area and the secret boss questline. Except, because of how most of the game is, I feel like there's little point in thinking about it because nothing else seems to really have much going on narrative wise. I dunno.

-Long term class balance
There was never a moment where I felt like I learned a real game-changer of an ability. There's not really a Rapid Fire or Doublecast equivalent where you feel in your bones you need to beeline directly towards it (even though Doublecast is totally in the game, it has a bunch of caveats that make its usefulness limited to specific situations). The closest was probably the Red Mage Warlock passive that lets you regenerate 6 MP a turn for six turns every time you enter battle; never took that off my casters once I got it. Instead I got these moments more from finding or buying fancy equipment, which is neat but not something I felt like I had control over.

This isn't a bad thing per se, I think it's definitely by design to keep the classes balanced, but it does flatten the curve a bit. I didn't feel like my party had crystallized into true shitwreckers until, when I reached the level cap towards the end of the game, I decided I was done trying to fill out jobs, stripped my entire party naked, and respecced them all into what I felt were the best versions of themselves. Did pretty well after that.

In conclusion, Crystal Project is pretty good (IMO).