There have already been a couple of Pokémon titles for the DS (Dash and Trozei), but so far there hasn't been a "real" Pokémon released for the system. That is to say, there hasn't been a traditional Pokémon RPG yet. Pokémon Mystery Dungeon: Blue Rescue Team comes close to the true Pok¿-experience (Pok¿xperience?), but it's actually quite a different beast.
Unlike the other Pokémon RPGs, there are no humans to be found in Mystery Dungeon (well, not really). You play as a human who wakes up one day to discover that he (or she) has been turned into one of the collectable Pocket Monsters and is now living in a world populated with the creatures, which you now have the ability to converse with. A brief quiz that you take upon starting the game determines which critter you become, and after choosing a partner from a short list, you begin your adventure.
As you start to unravel the mystery behind your transformation, you and your partner form a Pokémon rescue team that specializes in traveling deep into the many dungeons that dot the landscape. Your services are desired by other Pokémon that hire you to rescue trapped friends, deliver items, or other such jobs. Standing in your way are other Pokémon that have been driven to randomly attack passers-by after some inexplicable earthquakes. Eventually, rival rescue teams will reveal themselves as well, impeding your progress even more.
The new style of gameplay in Mystery Dungeon will initially confuse those who are used to the standard Pokémon titles. This game has more in common with slightly obscure "dungeon crawlers" like the PlayStation's Torneko: The Last Hope (which, like Mystery Dungeon, was developed by Chunsoft) and the PS2's The Nightmare of Druaga than the multicolored games in the Pokémon series. There is no journeying from town to town, no gym battles, and no snagging new friends with Pokéballs.