It's a grindy gacha game. Lotsa repeating the same content over and over again, and what characters you can get(summon) is completely random. Oh, and of course, there's tons of microtransactions. I haven't paid a cent, but I've also been very lucky. I mean, I just pulled Orlandeau today, and he's one of the very best characters in the game. However, he's a one trick pony, so I probably will only use him situationally since I already have Fryevia, who is also one of the very best characters in the game. I mainly just play it at work(I mean, what else am I supposed to do, work?) There is a story mode to go through, and it's very Final Fantasy, but they sure are dribbling it out very slowly.
I guess just be forewarned. FFBE can be pretty fun, but don't let it suck you in and waste all your money. Also, if you do get way into it, let me know. We'll swap friend codes and you can borrow my awesome Fryevia that way.