I've always considered myself a fan of the Castlevania series despite not really liking the original Castlevania or Simon's Quest so much. The first game in the series that really hooked me was Castlevania 3: Dracula's Curse on the NES. It was a fantastic game, and I ranked it 35th when I listed my favorite games of all time. Later, when I got my first Playstation, I picked up Symphony of the Night, which is in my opinion the best Castlevania game ever made. I ranked that one 14th. But recently, when I picked up Castlevania: Portrait of Ruin for the Nintendo DS, I found the third Castlevania game ever that I've loved.
Granted, a lot of what it has going for it comes because it's imitating Symphony of the Night. It's got lots of RPG elements, enemies with specific weaknesses, (fire/ice/light/blunt/edged/whip/et cetera) and some Street Fighter-esque moves. It's even got a couple of the same bosses, including Symphony of the Night's "Legion", a crazy giant sphere of zombie corpses.
It also borrows some elements from Dracula's Curse, namely multiple characters and magic spells. Sadly, you don't have a choice of three companions as you did in Dracula's Curse, but your single companion does have magic spells, as Syfa did. And there are some cool spells: flames, healing, summoning, protection, transformation, and more.
The various subweapons include the classic axe, cross, holy water, and knife, but there are a couple dozen, and once you find one you can switch at will. And as you kill enemies with each weapon, that weapon levels up. And when it maxxes out, the graphic for the weapon actually changes. In reality, I found very few of the weapons to be really useful - I stuck primarily to the good old axe, which has a great arc and can hot a lot of enemies. And for raw damage, they're never as good as the spells. Acid bubbles, Ice Needle, and Raging Fire are staples for taking down big baddies.
So it's not as good as Symphony of the Night, but it's the best handheld Castlevania ever. I'm having a ton of fun with it.