Super Castlevania IV
For fans of the classic series, Super Castlevania IV is an odd entry, one either beloved or hated. While in many ways an improvement over the games that came before it, benefiting greatly from the improved graphics and power of the Super Nintendo, other improvements from the earlier games -- such as the extra emphasis on exploration found in Castlevania II: Simon's Quest or the multiple characters and branching paths of Castlevania III: Dracula's Curse -- were omitted, making for a mixed-bag of ups and downs for some fans. Although generally considered a masterpiece of the SNES lineup, there are fans that wish the game had pushed the Castlevania series further instead of feeling like more a retread of the basics of the series.
Some of that feeling, naturally, comes from the fact that, in Japan, the game is considered a "remake" of the original Castlevania. It takes Simon Belmont back to his original adventure and then present him, and the players, with an entirely new version of the castle to explore. The team that worked on this adventure (who, it should be noted, would go on to found the much beloved gaming studio Treasure) wanted to showcase what the SNES could do for the Castlevania series going forward. They made detailed planning documents, going over every aspect of what they knew the SNES would be able to do (reportedly even before they had access to a development kit for the console) so they could hit the ground running and put out one of the best, and most loving, remakes they could for the SNES in its first year on the market.
Their effort did pay of, mind you, as this game is still considered one of the greatest SNES games ever released, showing up on a number of "best of lists" from various publications. The team behind the game made a title that looked, played, and sounded better than anything came before, and there are moments even now that look absolutely stunning in the game. This was a team that spent all their time crafting everything they wanted to do and then dumped every great idea they had into the title to make the best looking, and best playing, game in the series up to that point. Admittedly it's also one of the easier titles in the series (which is why a number of the hardcore players ding it -- it's not "Nintendo Hard"), but that easier difficulty did also make it more accessible, letting more people into the world of Castlevania.
When it comes to whether Super Castlevania IV is a proper remake or not, much of that confusion comes from the U.S. translation of the game. Where in Japan the game is known simply as Akumajo Dracula, the same title as the original Castlevania, here in the West it was given that "IV" at the end and the story was written as if the game fit in after Castlevania II. Plenty of fans of the series grew up thinking this was Simon's third adventure, and even Konami of America had it listed, for the longest time, as if this really were a third outing for Simon. It wasn't until later, when Koji Igarashi was in charge of the series, than an official timeline was produced for all regions, clearing up that confusion... sort of.
The thing is that there are elements of the game that don't line up with it being a direct remake. The castle, for starters, doesn't follow any of the same stage construction or rules, being a completely new entity this time around. Simon, too, has seen a number of improvements, gaining the ability to grapple and swing from his whip as well as being able to whip in all eight cardinal directions. He's his best self here, feeling oh so different from how he does in any other game. And there is the fact (as we've pointed out on the Chronology page for the title) that the intro of the game makes every indication that this title takes place after Castlevania II. Whatever the intentions of the team might have been, and even with a timeline that "corrects" this entry, it still does feel like Super Castlevania IV is a sequel, and not a remake.
Although sales number for the title are hard to find, it did reportedly sell well enough on the SNES throughout the console's lifespans, being one of the early big hits from a third party studio on Nintendo's sequel box. It's the fan consensus after that fact, though, that has defined the game's place in the series. It's not as big an evolution for the series that some fans might have liked and yet, at the same time, it was a big leap forward for the series in terms of graphics, sounds, and base mechanics. It's hard to argue that this is the classic series playing at its absolute best, with tight controls and responsive design. And yet, critically, there were those that wanted something more like the harder, classic games, which does illustrate why, after this title, the series took a step back (in some ways) with heroes that were a little less responsive, with stages that were a little more free-form but maybe didn't push the hardware as much.
That leaves Super Castlevania IV as a bit of an oddity for the series; a game unlike what came before or since but showing all the care and attention you expect from Konami. Whether an official sequel or not, Super Castlevania IV showed the promise of both the series and the hardware it was released on, and for that it is an absolute treasure.