One of the things I got for Christmas this year was The Legend of Zelda: Phantom Hourglass for the Nintendo DS. I've played the game for several hours now, and I wanted to discuss Nintendo's usage of the DS hardware in the game. Never before have I seen a video game make such good use of the hardware it has access to. Link is controlled entirely through the use of the touch screen (the D-pad and buttons are hardly, if ever, used), which isn't entirely a new idea; see Kirby: Canvas Curse for a previous touch-screen-only title.
What really blew me away (almost literally) was the usage of the microphone in the game. There are a number of places where the player has to take some action: call out to a character trapped behind a steel door, blow out a few candles, etc. The neat thing is that all of these actions require you to physically do something. When you are told to cry out, you have to literally cry out. When you are asked to blow out the candles, you have to literally blow onto your DS! Is this a genius idea or what? I know that Donkey Konga for the Gamecube used a microphone (where the player clapped their hands), but this is the first game I've personally played that makes use of this kind of hardware.
The game also uses one other hardware feature that helps to advance the storyline (I'll do my best to avoid any spoilers here). At one point, you are asked to perform a specific task to help locate a hidden item in the game world. In order to do this, you literally have to close the lid of the DS, and open it back up. What?!? Unfortunately, the game didn't give me enough hints to figure this out on my own (or I was too dense to make sense of the clues it was giving me). As a result, I got stuck at this particular point and ended up reading about how to advance forward (and I hate having to do that kind of thing). But this hardware hack really impressed me! It will be interesting to see if any other games make use of this technology; here's hoping that they will!