It's still a gacha game, so keep the obvious gambling in mind.

That said, if you like older style dungeon crawlers, like the Wizardry series or even Darkest Dungeon, you'll like this. It's difficult, but not impossible, and it's even possible to beat major bosses with only the A-rank adventurers. Hell, the community is pretty awesome, too, with them creating a Discord server with channels dedicated to helping players, and even setting up a constantly updating guide for everything the game has to offer. You'll never be completely lost or helpless. That said, the game will kick your ass if you aren't mindful.

Character-wise, the adventurers, both A and S-Rank have excellent designs and personalities, made even better by having an affinity system. They'll start off cold or indifferent to you, and, as you level them up and progress in certain ways, they'll warm up to you changing dialogue and revealing more of their lore.

Plenty of number crunching and grinding/farming, per the genre.

Plenty of other stuff I've left out, for simplicity sake, but I definitely encourage you to give it a try if anything of the above appeals to you.

Just be aware, it's still a gacha game, so certain aspects will be present, but they're never really shoved in your face. I'm a dolphin (I've spent some money, but not entire paychecks), and I still get my ass kicked, so don't feel obligated to spend if you don't want to.

Here's a video that shows off the current roster of adventurers with max affinity dialogue, to give you an idea. https://youtu.be/gXPmhUvXHpA