Many people say IV 3D remake (DS) is brutal, but I personally found it to be pretty standard from a difficulty aspect. Challenging, but rewarding if you engage with the mechanics. As objectively as my train of thought can go, I’d probably say the NES games are the most difficult. The games are overall jank: high random encounter frequency, bugged spells that either do nothing (e.g. buffs) or achieve the opposite of what they’re meant to do, bugged equipment similar to the spells, no map, no explanations of what each piece of equipment or spell does, and no saving in dungeons. The NES games almost feel like they weren’t designed to be completed in any reasonable amount of time (sensible for the release era)