The DS needs more games like Polarium. It's not just completely original, it's only possible on this hardware. It uses both screens effectively and the touch aspects are nearly a requirement. It's also the best puzzle game for the console.
The tutorial that begins the game (and you're prompted to complete every time you turn the game on annoyingly) is effective enough to get started. The premise is one that's so simple you're going to ask yourself two questions: "Why didn't I think of this before?" or "Why did it take so long for someone to make this?" Pieces, as they always seem to do in puzzle games, fall from the top of the screen. Once down, it's your job to touch and eliminate them so they can make space for the next batch dropping from the top screen. Create horizontal lines of either white or black blocks to gain points.
There are only two colors, so while it seems easy enough at first, this is actually brutally difficult, and if the concept isn't grasped quickly, there's no way you'll survive long enough to enjoy it. Making it out of the first scoring bracket will seem impossible for a while. You can try to take out your frustrations in multi-player, or in the even harder puzzle mode, which requires you to take out an entire screen with one slide of the stylus.
The only thing wrong with Polarium is that the way it's designed can be annoying. You need to stop making any moves above the line you just cleared and wait for the process to be completed. Otherwise, you'll be making more work for yourself by flipping squares you didn't want flipped when the line drops. It's also frustrating when the touch screen doesn't pick up a movement as you relieve just a slight amount of pressure, which is going to happen during a bumpy car ride. That's all it takes to lose a game.
The developers haven't put much effort into the look of the game, though that's not particularly important here. At least in the DS's other puzzler, Zoo Keeper, the pieces were made out to be abstract animals. Here, we get nothing but black, gray, and white squares. There are no fancy effects when pieces are cleared and the menus are just as plain.
Music is not varied (one theme for each section of the game), and it's repetitive. There's no need for headphones here. Sound effects don't fare much better; just basic noises to confirm your success. You could play this with the volume all the way down and not lose any of the experience.
What it lacks in aesthetics, it does make up for with gameplay. While it does steal the basic "blocks fall from the top" aspect of other games, it's how you eliminate them that make it special. This could be done with a mouse and a little Flash programming, but the stylus adds the accuracy the game requires. Just don't plan on a record setting session while driving to a vacation spot.