this game was released during that weird era before three houses where intelligent systems seemingly had zero confidence in anything fire emblem-related selling if it didn't involve their two golden geese on the 3ds + marth who gets a legacy pass in (which, given the state the series was in leading up to awakening, it's understandable, but still strange to look back in hindsight). as a result we're left with a rather bland playable roster that only covers 3 different games. two other characters can be unlocked outside of the story that represent two different games but it feels too little too late (also, i have heard that celica plays exactly like marth, which made me not want to bother unlocking her). more characters with different playstyles are available as dlc, which is also massively disappointing tbh
the gameplay is warriors-type gameplay with fire emblem elements, and it's perfectly alright in that front, complete with the repetition that comes with the genre
the story... well at the end of the day it's meant to just be a cute crossover, but there are some parts of the story that just recreate moments from the other games (like, there's a part where rowan falls off a very shallow cliff and the opening cutscene of awakening is recreated when chrom and lissa find him) and it's just..... so awkward, and dare i say it's a bit cringe. maybe some will get a kick out of that type of fanservice, but it was not doing it for me. would not recommend playing for the story lol
if you like warriors games and the cast of 3ds fire emblem you might get something out of this.