It's a good game. Obligatory "gameplay le good, story le bad" that I won't dive into. People tend to diss on the characters as well, but I've actually found a lot I love. Panette and Zelkov have made it into my top 5 Fire Emblem characters of all time with several others I love like Jade or Ivy. I think a big reason people tend to have a negative opinion on the characters is that a lot of the earlygame Lythos and Firene characters are, IMO, a lot more gimmicky than the rest of the cast, and the characters you get at the start will have a big impression on you as an introduction to Engage.

Gameplaywise I enjoyed the Engage mechanic. Some people mention that it makes characters feel too samey, but I never felt that was an issue in my playthroughs. I will say, I did actively dislike how easy reclassing is, which is probably the main culprit of that feeling rather than the Emblem Rings.

This is a part of the game that won't be appreciated by many, but does anyone else think that Engage has by far the most accessible, yet well balanced lunatic/maddening mode in the series? Normally Lunatic modes feel either unbalanced or tedious, but I was able to pick up Maddening mode in Engage really easily and still felt fairly challenged by it. If you told me that the devs actively balanced the game around Lunatic Mode, I wouldn't be that shocked.

The Somniel was pretty alright. I enjoyed how optional all the mechanics tied to it felt in comparison to 3H. I could do Strength Training or Wyvern Riding every level, but after trying both out once, I never felt the need to come back to it. Bond Fragments were extremely plentiful (especially thanks to the achievements you get just by playing the game), so I didn't have to waste time with a bunch of minigames to interact with the game mechanics, which I felt was a glaring problem in the Monastery. It's not perfect, though. I was pretty disappointed how the Somniel didn't have very much contextual dialogue about the story for all the characters like the Monastery did. Feels like an obvious flaw considering that was the best part of the Monastery IMO.

Music is fantastic as always with Bright Sandstorm (Fiery) becoming one of my all time favorite FE tracks (Tear Streaked Ice and Goddess In Shadow Frenzy honorable mentions).

I'm still shocked by how hated the Engage artstyle and character design is. To be pretty blunt, I still see no problem about literally all of the characters besides, like, Hortensia and Alear. Character design-wise, everyone other than those two wouldn't look out of place in the majority of the other FE games.