This is a really solid game that set the standard for most of the fire emblem series. Book 1 is just a remake of the first game however book 2 covers the aftermath of the first and expands on the world. You should definitely play book 1(or shadow dragon that game is probably better) since a lot of the characters are still relevant in book 2 and so you can have those "oh shit that dude that carried in like half the chapters in the first book is now a king" or "damn those 2 mercenaries that carried me in the other half of those chapters became friends and now they had a falling out" type moments. It's nothing ground breaking but it's nice to see characters you've known and used get developed a bit and feel like they fit in the world rather than being random guys that just so happen to join you. Most of the new gameplay fixes are good however mounting units are pretty unnecessary and I get that its purpose is suppose to balance the class system but it just makes indoor chapters slower. The lack of an item storage on the map like a tent also bothers me as it was in the first game but it doesn't change anything much and I guess it balances out being able to easily swap items out before a chapter begins and that is a godsend. The sprite work and animation are pretty and the aesthetic of the final boss in book 2 is absolutely spectacular. The book 2 OST is very well done, particularly the battle themes are fucking great, book 1's OST just mimics the original NES so it's whatever. Overall it's a very enjoyable game if you're into Fire Emblem and if you're especially into the older titles it's probably a must play.