Alright, just beat Final Fantasy IV Pixel Remaster. Thoughts:
Good game, it gets better as it goes, especially when you have your final party and you start getting their final equipment in the final dungeon/summons for Rydia, but wow, is FFIV derivative (or, to be charitable, iterative) of FFIII in many ways. The final dungeon is an easier version of III's final dungeon and Eureka, in that there's weapons locked behind tough optional bosses, but you get a save point a few floors from the final boss as well as the ability to buy Phoenix Downs (and I think you can buy Ethers, but I didn't have to use those other than when I was getting Bahamut, and I could've got by without them, frankly). Also, hunting down the summons was done in FFIII already down to who several of the summons themselves even are. Basically, the main new thing IV brought to the table was the Active Time Battle system (which is not nothing, I love ATB and this game pioneered it, and that's to its credit) and being on more powerful hardware, giving us fantastic music (and better graphics, I suppose, though I prefer the style of the NES games, though none of that really applies to the Pixel Remakes as they're all fairly similar presentation-wise as mentioned upthread). All of which is to say I suppose III iterated/was derivative of I, so criticizing IV too hard wouldn't be fair, and I don't really intend to. It just has never been a favorite of mine, and this playthrough didn't make me think any differently.
Also re: Edge, I ran into the same situation as Peklo - Rosa was doing a ton of damage by the end with her Elven Bow and Artemis Arrow, which was... weird, but kinda neat (always love to see healers do some deeps, m i rite ff14 fans?), and Kain was outdamaging him too at least when he got the Holy Spear, and Rydia was doing boatloads of damage whenever she did a summon or casted a spell, so... Edge was still sorta dead weight. Fuma Shurikens did decent damage against Zeromus, but I only had 5, then he was doing 2nd least damage per turn after those were used up. Can you buy more Fuma Shurikens somewhere? I didn't find a shop that sold them, but then I didn't get the achievement for going to every map location, so I may very well have missed it.
I love the Pixel Remakes so far, honestly. They're a great way to play these games, even if they all trend easier than the original versions (and in many cases, earlier remakes). Cannot wait for V and VI!