Even if you have played the previous games in the series, it would be a horrible mistake to miss Dawn of Sorrow.
The game follows the tale of Soma Cruz, who discovered a year ago that he contains the power to become the new Dracula in his body. Not wanting to do so, he has fought to contain the evil within him. However, a mysterious new cult has appeared that threatens to cause the rebirth of said evil. In light of this, Soma and his friends set forth to prevent that from happening. The plot doesn't factor into the game quite that much. Generally, you just explore the castle as you would if there were no plot at all, being held up at different times by rather convenient roadblocks. You do run into other characters occasionally, but this usually just results in more dialogue followed by the continuation of gameplay as if nothing had happened. Watching Soma's fight to contain the forces within himself is interesting enough to carry the plot, but it's the gameplay itself that makes this title so compelling.
As said before, Dawn of Sorrow is a platformer in the vein of the Metroid series. You explore the castle on your own, never once getting any major hints on where to go, except for an occasional hint disguised as a plot point. An automap is displayed on the top of the screen for you to keep track of where you've been and prevent you from getting lost. This can be swapped with a stat screen if you feel so inclined, but the map is more useful. The RPG elements generally don't lean towards that much repetition, as you're probably bound to pick up enough experience fighting enemies as you backtrack through certain areas of the castle. However, you will find that while an obsession with leveling up isn't by any means necessary, it will make boss fights easier if you power up just a bit before taking them on. Buying weapons and items to make Soma stronger and keep him healthy is possible in a store located in a certain part of the castle, but you'll discover that many (but not all) of the same items can be found for free around the castle whenever you'll need them, making money hunting seem just a bit unnecessary most of the time.
The most unusual feature of the game is it's Soul System. With it, you can absorb the souls of defeated enemies to make Soma even more powerful. Different souls give you different abilities, some of them allow you to summon monsters to aid you, others allow you to use new weapons and objects, and some of the most important ones allow you new abilities that get you through areas that were previously inaccessible. Souls tend to appear rather randomly, aside from most boss fights, but you'll find them to be incredibly helpful. You also have the ability to fuse either extra or unwanted souls with your weapons to make them more powerful. Doing so is an irreversible process, but it makes your weapons much more powerful than they would be if you simply left them as they were, and allows you to make Soma much more powerful than you could by simply leveling him up. It's annoying how rarely some souls appear, though that could have a bit to do with how often some enemies appear, but the soul system has enough creative twists and turns to make it fun to tinker with and make soul hunting seem worth it.
The DS' touch screen has a few uses within this game. You'll discover first of all that you'll need to use it to draw magic seals to finish off boss characters. Failing to do so will cause the boss to regain HP instead of dying off completely. Doing so can be incredibly frustrating at first, as the game appears to be incredibly finicky about how well you draw the seals. This becomes especially aggravating as the act of doing so appears to be nothing more than a tacked-on excuse to use the touch screen. However, it becomes clear soon enough that the game puts more emphasis on how quickly you draw the seals than how much attention to detail you give them, and the feature can be mastered and written off fairly quickly. You'll also come across a few areas where you need to use the touch screen to carve a path through ice blocks that get in your way. This is done easily enough, but it doesn't really lend itself to very much challenge, other than some occasional trial and error with no real consequences. Most of the touch screen functionality in this game feels like it was merely added by the developers in an attempt to give the player something to do with the DS' more unique capabilities.
Graphically however, the game utterly shines. It's clear that the game looks much better on the DS than any of the GBA Castlevanias ever did. Everything has a highly detailed, vividly colored look to it. There isn't a single enemy or object that doesn't look like it's taking full advantage of the DS' power. Every bit of gameplay takes place on the bottom screen, so there's no looking back and forth at the two screens during gameplay other than to glance at the map when you feel it's needed. Everything animates smoothly, and there's a lot of detail in the different shades of color that you'll find in the different areas of the castle. You'll notice quite a lot of detail in the larger boss characters, who often seem to stretch the game's art style to it's limits. There are also a few three-dimensional backgrounds located in some areas that are a very nice touch. The graphics are a very high point in this game, but they don't overshadow the game itself, rather, they compliment it as well as anyone could possibly ask.
Sound is a small step below what's found in the visuals. There are number of very good songs in the game's soundtrack, but none of them feel that memorable. Nearly every area does have it's own unique tune, which is a nice touch. Still, there's nothing utterly mind-blowing there. The sound effects do the job very well in this game, though they tend to blend in so that you don’t notice anything unusual about them after a while. There are a lot of voice samples to be found in this game. Nearly all of them take the form of different shouts and cries that Soma comes out with when he performs attacks or gets hurt during gameplay. There aren't any fully-formed sentences or anything like that, as dialogue is always printed instead of spoken. You might find yourself annoyed by Soma's voice samples eventually, as there's no way to turn them off and he always speaks whenever he performs an attack. But with this current generation of consoles and handhelds, you're probably used to that by now.
The main quest in this game isn't terribly long, it'll probably take you around ten hours to finish it the first time through unless you insist on collecting absolutely every single item and soul that you come across. There are a few handy unlockables to be discovered when you finish the game though, and this can give the game a bit more life beyond it's initial offerings. The core game in itself is worth the price of admission alone, but the unlockables manage to make this game a must-have. Even if you have played the previous games in the series, it would be a horrible mistake to miss Castlevania: Dawn of Sorrow. It proves that there's still a lot of life left in the Castlevania series, and it’s totally worth anyone’s money.