Birthright lets you lets you grind characters with optional missions. There is little mission variety, and not terribly difficult. Conquest is like the first FE game on GBA, no side missions, no easy mode, but more mission variety Consider it the Dark Souls version of Fates: demanding, but satisfying. Revelations is the complete package, and tells the real story from what I read, and it is the one I would go for; but I think it's dlc.