Here's some of my thought on the game. (This my first time writing something like this so forgive me if I did something wrong)
Graphic wise, it's really good. Though it might not look as... clean? smooth? HD? as the character models in HW but it's still good in my opinion. However, the lighting in certain maps might make it look weird. A very obvious example I notice is Leo's victory screen in certain maps. The shadowing from the lighting makes his face looks unfinished... A side note is that the bronze swords look so jarring lol
Music wise, it's amazing. I only wish they had some ost as it's own thing instead of a medley like how ID purpose is only part of the awakening medley and not it's own ost.
I'm mostly fine with voice acting. I don't usually complain about the voice acting and I usually find it funny when they sound "bad". An another note is that English voice lines seems to be softer than Japanese ones but I'm not too sure.
Gameplay is better than HW in my opinion. In HW, you are limited to only 1 character per mission (except 3ds version i think but i never played that one) but in FEW, you get to play up to 4 characters in one mission (1 or 2 in some history modes) so there's a lot of variation in it. Other than that, the strategy element in FE is really great in a warriors game. I don't think this was present in HW where you can command where they go and everything but this is really helpful in FEW. I didn't use this a lot when I play the story mode first in the Japanese version but after learning how great it is, I managed to beat final boss hard faster than I first did it. Pair-up system might be a little OP? At least for dual guard, since you can really get a perfect run easier with it. One thing that really annoyed me recently is whenever your allies are low on HP, the game keeps spamming "xxx is in trouble!". As if everyone of them is Genji spamming "I need healing"...
Story is alright. Nothing spectacular but it's alright.
Difficulty is perfect. You get missions that you can just plow through them or you get those that takes a longer time to beat or at least S rank.
I know I'm probably beating the dead horse and I'm not really too bothered by it but it did happen a few times is that all lancers are fliers. It's like they know all your lance units are also fliers so they decide to beat archers within sword enemies in some missions.
My favorite part is this game is definitely development between characters. The support are really well-written and hilarious, especially cross-game conversations. It's something people kinda hoped for in the support update in FEH but we didn't get but FEW managed to do it and did it well.
All in all, I really like this game. Even though the character roster is something that made a lot of people lose interest in the game but past that I think there's a lot of great feature that players can enjoy.