Honestly, when I first heard a Castlevania fighter was in development, I was thinking along the lines of Darkstalkers, Guilty Gear, Marvel vs Capcom, etc.; a traditional 2D fighting game with an interesting single player story and pretty much endless possibilities for tournaments. Castlevania has a good roster for that sort of thing, and enough environments to make it happen.
A 3D fighter with selectable weapons like Soul Blade or SoulCalibur would also have worked, and even the free roaming brawler formula they picked isn't intrinsicly flawed; I hear Power Stone remains popular, and the Dissidia Final Fantasy games are a fantastic way for Final Fantasy fans to waste time, though they are flawed and limited in move selection, the games got around it by animating the characters in such a way that they still move dynamically, with secret chain combos that can be activated by meeting certain combo requirements and such. The Dissidia games have limited actual combat movesets, but they are still entertaining to play, and on PS360, they would have rocked even more. Adding in little nods and in-jokes to the character's respective games, like Tidus mocking the Emperor's infamous death cry ("What's with this unguAAAAAAAHHH business?") or the characters mocking Exdeath's worship of the Void really brought the games into their own own.
And yet, why do I enjoy the Dissidia games and hate Judgment so much? Dissidia was made for the fans, and every decision was made knowing that pretty much ONLY the fans would even play the game. Judgment seems like it was all about compromise, trying to keep it competitive on the market in a world of fighters and shooters, and hoping the "Castlevania" name would sell it a few copies more. No visible consideration was given to the fans of the series. It spent much of it's time committing similar sins as Lords, which is evident in the wildly stupid character designs that do not resemble the originals, the anime-inspired art style, and imitation hard rock soundtrack. It spends so much time aping other fighters, any Castlevania references felt like last-minute additions. Under IGA, the references make more sense than Lords, I'll admit, but still, whips and names aside, it hardly feels like a Castlevania game, but rather like someone slathered a Castlevania paint job on the halfway dim bastard love child of Power Stone's gameplay engine and Kingdom Hearts' character designs.
And I think that's where Judgment committed it's greatest sin; Smash Bros., Dissidia, Marvel vs Capcom... all those great mash-up fighters were made for the fans of the franchises represented. They are (usually) crafted with love and care, with attention paid to how everything worked, and furthermore, the characters are accurate to their original portrayals, so fans could have their fun.
Judgment was made for the fistful of yen it might bring home. The fans were barely even considered. The characters couldn't have been more different. The story was nonsensical. The whole game was a mess the fans ended up not really wanting. By alienating the only people who would have been CERTAIN to buy the game, Konami destroyed any chance of ensuring a competitive fighter on the market. Newer gamers were put off by the limited nature of the game, and an outright sadistic single player mode that delights in tormenting you as you flop towards the finish line. Old fans were put off by those same things, but also how the game portrayed and treated the characters and story.
Instead of being a celebration of the franchise, Judgment wound up as a cruel joke mocking it.
This needs to change if there's ever to be another attempt at a Castlevania fighter. It needs to be made with the fans considered above all else, as those are the people who will buy the game. Anyone else is a welcome accident.