Trading in Castlevania's trademark 2D action for 3D is a fool's bargain. At least, it is if Curse of Darkness is any indication; the body is willing, but the heart is all but missing.
The story, a tale of competing vengeances between two of Dracula's henchmen, is serviceable in that it motivates the new hero-in-puffy-shirt, Hector, to hack and slash his fashionably gothic way from one ghoul-filled area to another. But it's the collectible materials dropped by slain monsters, and the items Hector can forge from them, that keep it interesting over the long haul. The item-creation system goes pretty deep, with lots of variety in the resultant shiny things, particularly when it comes to weapons. Discovering new materials breathes a huge amount of life into the usually dull business of managing items. The same goes for the "Innocent Devil" sidekicks you'll acquire regularly; each devil (think demonic Pokémon) grows and evolves differently based on what you feed it, affecting what skills it develops to aid you. Some can open locked doors or carry you across chasms, and some just offer more creative ways to killerize your foes.
The problem is that collecting materials, fashioning sexy new goodies and determining the growth of your little devils are all considerably more enjoyable than the actual combat and exploration. The surprisingly tedious level designs don't help matters any. Gone is the excitement of exploring the next gorgeous environment and soaking up its aesthetics. It still looks sharp, but the endless succession of same-y corridors and paths, all lacking any meaningful detail, just dulls the senses.
The process of re-deadening the undead creeps that populate Castlevania also becomes repetitive. The beasties look good, but most are so dimwitted that mercilessly pounding the attack button is more than enough to shred them. This stratagem works so well, in fact, that you don't even need the fancy chain combos you can trigger using your Innocent Devils. The only real challenge comes from the boss battles, but even then it's mostly because the awkward and inflexible camera is hell-bent on trapping you in a corner. The ability to just pull the view back a bit would've made a tremendous difference.