For comparison's sake, say Zelda II: Adventure of Link and Final Fantasy II are the Neanderthal of their respective evolutionary lines, while every other episode that came after in both franchises are the Homo Sapiens and their descendants. The Neanderthal, despite being evolved from the same root DNA, went extinct after a short while and did not influence much, if at all, the DNA of what came and remained after them. That does describe Zelda II and Final Fantasy II and their weird systems quite well indeed. Well, Fire Emblem Gaiden, the second episode in the series, is very much in the same category as it represents a side-step in the evolution of the series. An evolution of the formula of the initial episode that came before it, but one that didn't lead the series anywhere for its future, as the formula went back to its roots soon after to never return to the odd recipe introduced in their second instalment.
Zelda II and Final Fantasy II are both kind of black sheep nowadays to most fans of their respective universes, due to them feeling so different and unlike what decades of their franchises have made them accustomed to in terms of expectations. There is not, however, any truly comparable consensus where Fire Emblem is concerned, simply because the series remained bound to the Japanese market for such a long time and, as such, few, if any, modern Fire Emblem fans have even heard of Fire Emblem Gaiden, which released on the Famicom all the way back in 1992, when the Super Nintendo was already out pretty much everywhere in the world and most players had already moved on from the 8-bit generation.
The reason the subject of Fire Emblem Gaiden and its being a very odd episode in the franchise is brought up is, of course, because Fire Emblem Echoes: Shadows of Valentia is a full on remake of this game. In the West, gamers have indeed been missing out on several of those older releases in the series. It is, therefore, with a lot of curiosity that this game is approached today since it is effectively the Zelda II of the Fire Emblem series, a comparison already commonly drawn for good reason among the few fans that did experience it. For one thing, it introduced free world map travel, allowing players to return to previously visited places. This should sound familiar to those who played Fire Emblem: The Sacred Stones and Fire Emblem: Awakening, but they should take note that this would go unused for the five mainline entries that came after it.
It did away with weapon durability, which only Fire Emblem: Fates and, ultimately for simplicity's sake, Fire Emblem Echoes would not reuse, either. Instead, each character has a default weapon based on its character class always equipped, and only one item slot to carry something else, either a consumable or a different weapon or accessory, like a shield or a better sword than the default one that will, therefore, give either a defence or stat boost. Even more unique is that characters gain in proficiency with that secondary item, unlocking special skills for that character over time, something that wasn't present in the original. Another aspect that was unique to the original, and which, therefore, makes a comeback in this remake, is that magic spells drain the user's HP. Not much, at least not early on in the game, yet it does change the way that mages are approached.
Although, with that being said, they do tend to be overpowered compared to the hordes of bandits with low resistance to magical damage that the player will have to take down. It's worth noting as well that, like the original, there is no magical power stat, magical damage being calculated instead from the sole "attack" stat that encompasses both physical and magical damage, just like in the older titles. While this may sound like a drawback, it actually plays in favour of the open-ended re-class system that the original was the first to introduce to the series.
It is indeed possible to re-class a character while praying at statues of the goddess Mila. New to this remake, though, is the notion of fatigue. Although it was once used in Fire Emblem: Thracia 776, where it had the potential of preventing a unit from taking part in a next chapter, here it does seem to only affect the user's ability to "fight well" according to the game itself, which does sound like it will not affect damage dealing per se but would affect accuracy and the capacity of the character to dodge incoming attacks, although this is not made entirely clear. Fatigue can be relieved by eating or drinking, or by making an offering at, again, a statue of the goddess, found inside dungeons. Speaking of which, the defining element that sets it apart from the rest of the franchise, much touted in the reveal trailer, is dungeon exploration. Originally displayed in a top-down view, reminiscent of Zelda/any JRPG of the 1980s on the Famicom, those are now fully remade in 3D.
Players can move around those by directly controlling Alm or Celica using the Circle Pad, while the D-pad on OG 3DS systems or the C-Stick on New 3DS controls the camera. Either hero can use their weapon to smash crates, barrels, as well as flowers and strands of grass, to reveal items and coins that can be picked up, Zelda-style, for later use. Such dungeons are populated by enemies that engage combat by making contact with the hero being controlled, which then triggers a battlefield, in the same Fire Emblem style, against a small number of said enemies. Once the battlefield is cleared of all enemies, the game goes back to dungeon exploration.
Overall, a lot of the things that have been added over time to Fire Emblem through subsequent releases, but which were not yet part of the series at that point in 1992, are either not back altogether, or are added on top of the original through new mechanics. The weapon triangle that has become so important over the years, and synonymous with the series, for instance, is absent here, simply because it didn't exist yet at that point when the source material came out. Early hands-on with this remake does not hint at marriages and children being part of this game, either. In fact, character relationships are not being put to the forefront here like in other, more modern entries, with character interactions like support dialogue only happening between units straight on the battlefield, as was the case in older games before the days of Fire Emblem: Awakening, making this one more of a throwback to older generations of games but while still adding enough on top in terms of new content that barely anything of the original remains apparent.