The gameplay is good. There's a distinct binary attack range where you can either attack at 1 range or only at 2 range being a bit weird, and also that the there's mainly two movement ranges, 2 or 3, making characters that can move 3 way more versatile, but otherwise I don't see any problems with it. I don't think there's any terrain battle modifiers too so that also simplifies things a lot.
It won't be as well balanced compared to a traditional FE game because your team strength is mainly determined by how many overpowered characters you gacha'ed. So difficulty seems fairly arbitrary for the most part, perhaps until the lunatic or late game maps you have to grind.
Edit: Perhaps the main gameplay would be getting a fairly big roster of 5* characters that you can switch around to specifically tackle maps with particular enemies near the end. Lots of specific unit counters like armorslayers maybe.