Many of the characters in Judgment seem like caricatures of themselves, their designs clearly influenced a bit too much by Soul Calibur.
Perhaps the most fundamental design issue a fighting game faces is character balance. Both the enjoyability and longevity of fighting games depend greatly on how much strategy reveals itself upon repeated plays against a variety of opponents. The subtleties of characters in games like Street Fighter 2 and Soul Calibur took months, or even years to deeply understand, and such understanding can only come from massive amounts of play from an eager community, and ever-evolving strategies.
Of course, the game must be enjoyable and rewarding enough to elicit that level of dedication, but this is encouraged by an inherent depth. Although little time has passed since its release, Castlevania Judgment does not appear to display either fundamentally balanced characters or deep gameplay. Partially as a result of this, it certainly doesn't feel enjoyable enough to become a fighter (or potential franchise) with a good deal of longevity.
To be fair, that may not be its intent. For years now, the Castlevania series has been characterized largely by regular releases for portable consoles, all subscribing to the framework first applied to the franchise in Symphony of the Night. This has served it remarkably well, and virtually every 2D Castlevania, particularly those released since Symphony, has been very successful, both commercially and critically. The most successful 3D entry in the series was arguably Lament of Innocence for the PS2, perhaps because it largely followed the example set by the well-regarded Devil May Cry.
With that in mind, then, the choice to present a 3D Castlevania fighting game seems strange. On the surface, it appears to simply be an effort to bring Castlevania to a genre that has proven itself quite capable and enjoyable in 3D. But given that Lament of Innocence has indicated that the series can be somewhat successful in 3D anyway, this kind of experiment seems unnecessary. Further, Judgment simply doesn't have enough of the qualities required of a successful fighter to appeal to fighting game fans. It may fare better with fans of Castlevania in particular, but it bears some examination whether or not the mythology of Castlevania really lends itself to more traditional fighting game design to begin with.
This would not really matter if the game had demonstrable depth and staying power. A lot of character and narrative silliness in games in general (and perhaps fighters and platformers in particular) can be forgiven if the fundamental gameplay is fun. Without this, however, Judgment relies solely on its brand to engender interest and attachment. For this to be accomplished, though, would require the game to feel like a natural extention of the Castlevania universe, and to be immediately recognizable to fans. Unfortunately, some design decisions wind up distancing it from the Castlevania mythos, rather than offering it a new view of it. With each new graphical advancement in Nintendo titles, for example, Mario simply looks more like Mario. By contrast, many of the characters in Judgment seem like caricatures of themselves, their designs clearly influenced a bit too much by Soul Calibur and other modern action and fighting titles. Some of these characters haven't been seen by fans in a long time, but it's difficult to imagine that they look like they're presented in Judgment.
In the end, the main issue is that it feels as though nobody really decided what exactly Castlevania Judgment was supposed to be. On the one hand, as a fighting game, Judgment simply lacks the depth requisite of classic examples of the genre. As some sort of all-star, Smash Bros.-esque affair, it comes up short as well, simply because the world of Castlevania isn't really comprised of all-stars, and Judgment never quite feels like it belongs alongside other Castlevania titles. At the end of the day, it might be of interest to die hard series fans, but it exhibits limited appeal beyond that.