After getting Engage about a year ago, I finally got around to finishing the game. I cleared it on Maddening with liberal use of the Turnwheel and resetting the game for character deaths, but I think it would be very rewarding to attempt an ironman run in the future.
My initial impression wasn't very positive. I'm not a fan of the artstyle in general (I liked Echoes and Fates' art direction best in the series), the story was really uninspired (as everyone has already pointed out), and the game's mechanical distinctness with Emblems, Engage, subclasses, and break occasionally frustrated and confused me as I was learning how to play.
The story was really basic and cheesy - which doesn't really count as a strike against it in my book - but a lot of the execution with big reveals and dramatic moments was so poorly contrived that it took away any possible pathos you could've possibly gotten from them. The Brodia arc and its supporting characters were a high point of the story. The characters surprised me a few times in their supports. I liked how human they felt once they had a bit of time to escape their very limiting characterization in the main story itself.
However, the gameplay was incredible. I haven't had this much fun playing a Fire Emblem game since 2017 with Fates (Conquest). The Emblems give this game such a cool flair with crazy abilities that the enemies fairly balance out with their own out-of-the-box abilities like multiple health bars, moving around the map, or in some cases using Emblems themselves. The map design gave a lot of varied objectives with Chapter 11 being probably the best map I've ever played in an FE game (it beats out Conquest Chapter 10 if only because Conquest Chapter 10's map isn't integrated into the story in nearly as awesome a way). I wasn't a fan of reclassing in this entry or 3H, but at least it required significantly less grinding and teacher's pet nonsense in Engage to put Kagetsu on a dragon. I was also very impressed with their solution for grinding out class skills in Awakening and Fates by tying them to the promoted class at Level 5 and making them non-transferrable.
Some UI things annoyed me throughout the run - namely that tonics needed to be bought individually, the arena didn't let you skip the character introductions before every single fight (I've memorized all of Kagetsu's dialogue at this point), and the Emblems only being trainable in increments of 5 levels was positively baffling.
Overall, I would rank this game very highly - up there with Fates: Conquest - and I hope IS implements some of its excellent features (Engage abilities, subclasses, break, the limited class skill system) into Fortune's Weave.