It's pretty good. It fails to hold up perfectly to the original, but it's pretty good.
Arkanoid DS revisits the simple gameplay of Taito's arcade classic. It's completely self-evident: you see your paddle (the Vaus) on the bottom, blocks on the top, and a ball in the middle, and you know from the first second of play that you're to break the blocks with the ball, using the paddle to direct it, and keeping the ball from falling. The DS game stretches the action across both screens, with the block structures (colorful arrangements of blocks placed either to be challenging or to make a picture) on the top screen.
The resultant increase in the vertical playfield space has been combined with a sharp decrease in the horizontal space: basically, the playfield has become much taller and narrower. This means two things: first, that the ball ricochets off of the side walls much more than before, and second, that your Vaus has much less distance to move. It makes the game much easier, since the ball does more per move, you effectively cover more of the space to start with, and don't have far to go to catch the ball. The size of the playfield varies by level, but it's always pretty narrow.
Reshaping the levels isn't all that Taito did to make Arkanoid easier. In previous incarnations, you were given a number of lives, which decremented every time the ball fell past the paddle. After dying, you'd start again with the ball positioned on the paddle and your progress saved, until you ran out of lives and the game ended. High scores (and a grey powerup) increased the number of lives you had.
Arkanoid DS's lives manifest as a bumper under the paddle that stetches across the whole playfield. If you miss the ball, it simply bounces off the bumper back up into the level. You have a supply of three bumpers that refreshes in every single level instead of a persistent supply of lives. In essence, all of the challenge has been stripped out of Arkanoid DS. Arkanoid was once really hard, and the lack of challenge hurts.
It's a shame, because there are a lot of really compelling new features that add a lot to the experience. Branching paths allow a lot of replayability and customization of the game -- the game contains 28 different sets of five levels. The in-game shop reveals the somewhat antiseptic visuals to be a feature: the fact that the basic appearance of the game is kind of bland helps motivate you to earn in-game currency and spend it on wacky new block shapes (like Space Invaders), backgrounds, level frames, Vaus shapes, and even sound effects. I couldn't get rid of the boring all-white Vaus and replace it with a proper silver-and-red model quickly enough.
Oh, and it's also got online multiplayer. That is a pretty significant new option.
Of the three control schemes, the one that makes the best use of the DS's prominent features is also the most awkward. Dragging the Vaus around with the stylus feels imprecise. To combat visibility issues, you can drag from anywhere on the screen that is vertically aligned with the Vaus. It works, but moving something that you aren't touching takes a bit of getting used to, and sliding rapidly back and forth will result in a slip of the stylus occasionally.
Surprisingly, the directional pad control scheme isn't bad. Taito cleverly compensated for the lack of analog control in this mode by assigning a speed-up function to the shoulder buttons. The learning curve seems shorter than the stylus method, and doesn't obscure the screen at all.
The third option, of course, is the import-only paddle controller. If you have even a passing interest in getting Arkanoid DS, just go ahead and get this controller -- this is a Square Enix game after all, so it's not ridiculous to pay $40+ for it. The paddle works perfectly, with a smooth, ball-bearing-assisted. It's basically the Hori Real Arcade Pro of portable paddle controllers. I had the disadvantage of starting with the paddle, which made the other control schemes seem offensively awful in comparison. I warmed up to them after separating myself from the paddle long enough, however.
My total experience with the game is similar to my feelings about the "normal" control schemes. At first I thought the paddle was the best part and the game was a bit boring, but as I played I saw Arkanoid through the sheen -- the cute block layouts, the classic powerups (laser, catch, extend, slow, etc.) and began to feel more positive about the game. It is absolutely too easy, and people who have played things like Break 'em All may miss the bosses and other bizarre non-block challenges, but this is Arkanoid with new levels and online play. And a paddle controller. Even if you're flying through the levels, you'll probably have fun doing so.
Final score: 7/10