Going Forward by Looking Back
Castlevania II
If it wasn't obvious by the sites I run (Castlevania RPG and the Inverted Castlevania Dungeon), I'm a huge fan of the Castlevania series. I really like the older titles (even if I suck at them) but the newer, Metroidvania titles are good in their own right (by and large). I do tend to think the series has lost its way in recent years, especially with the reboot, Lords of Shadow series, but no matter the highs and the lows I will always be a fan.
Sadly, it does seem like Konami is losing interest in the saga. The Lords of Shadow sub-series has gotten decent reviews and okay sales (from everything I can find), but Konami let their lead designer for the series, IGA, leave for greener pastures (basically so he could go off and make Metroidvania games on his own). They've also commented that consoles are not their focus -- mobile is, and who knows what that means for the venerated series I dig so much.
It does get me thinking that the Castlevania IP is still viable, it just needs the right leader taking the reins. So if I might make a suggestion, Konami, let's go back to the beginning (more or less) and take a stab at what you used to be so good at. Let's make a much more classic game like the ones of yore.
My suggestion, though, might bother some purists. I don't think we need a remake of the original game in the saga. Hell, we've had a ton of those, certainly not the least of which were both Castlevania Chronicles (itself a remake of an older remake) and Super Castlevania IV (if you buy in that it's a remake of the original and not a sequel like I still contest). No, let's take one step forward and look towards Castlevania II: Simon's Quest for our remake to help draw attention back to the series (and maybe bring some business in for dear old Konami).
The first question should be, "why on Earth would you want to remake Simon's Quest?" Let's face it, the game is really not that good. The original is clunky (like the old Castlevanias were at their worst), difficult, and just hard to get through without a strategy guide and a better translation than the one Konami originally provided. The game has issues, no doubt.
The reason I think we should take another look at CV2 is because it's a connection between the old games and the eventually Metroidvania series. The game features an pen world, RPG elements, and a pace unlike the other games in the series. It was Metroidvania before that was even a thing. A good remake would bring in the fans of the classic series as well as those people looking for another fix of Metroidvania goodness.
So how would we want to proceed? Well, firstly we'd want to update the graphics. Not just a 16-bit style spit and polish like Adventure ReBirth got. No, if we want Simon's second adventure to shine, we'll need to give it the Symphony of the Night treatment. This game needs to be pretty and, in the process, Simon has got to be smooth as silk to control. This game has to outshine most everything that came before.
In the process, let's give the game a whole new translation. The old one was terrible, with clues that were impossible to parse. Let's remove the mystery, make the secrets a tad easier to find (and maybe hide a bunch of new stuff in there), and make everything easier to understand with townsfolk that will give advise you can actually use. Sure, throw in some references to the old, terrible translation as a way to say, "yeah, we're in on the joke, too." Maybe put a graveyard duck somewhere in there for the hell of it. But make the game make sense.
And then, while we're at it, let's make the RPG system work. In the original your currency was also your experience so often it was a choice between purchasing items you needed or gaining a level. Let's streamline and separate the money from the experience. All the later games made it just that simple, so it doesn't seem like a step in the wrong direction -- you're just course correcting for the Metroidvania crowd.
This could be a game that works, and heck, it's a savvy move, Konami. With all the remakes and sequels already in the series, the one game no one would expect you to revisit is Castlevania II. You could get some interesting PR and make a game that bridges all your fandoms and demographics. Go forward by looking back.
And hell, you never know, the game might just sell well enough you could even make a third official game staring ol' Simon. He's bee retired long enough -- let's bring the original hero out for another round, eh?