Mario & Luigi: Bowser's Inside Story

Mario & Luigi: Bowser's Inside Story (Mario & Luigi RPG 3!!! in Japan) is the third installment in the Mario & Luigi series and the second to be released on the Nintendo DS. It was announced during Nintendo's October press conference. It was developed by AlphaDream and featured, for the first time in the series, Bowser as a playable character. The babies from Mario & Luigi: Partners in Time are no longer present.

Gameplay
The game will have players taking control of Mario and Luigi together and Bowser separately. In the game Bowser, while mind-controlled by Fawful, seems to have engulfed Mario, Luigi, and copious other denizens of the Mushroom Kingdom using his new vacuum power. Meanwhile, the entire kingdom is facing a disease called the blorbs (known as the Motakoro disease in Japan) that causes its residents to bloat. Mario and Luigi will be controlled within Bowser, and it appears that this portion of the game will be a sidescrolling game, while Bowser's section will include a traversable overworld.

Characters
So far three characters have been confirmed to be playable, and in all likelihood this is the final number. Mario and Luigi are of course returning once more, though in a surprising twist Bowser will once again appear as a playable character. This isn't the first time that the usual antagonist has appeared as a playable character. In Mario's first RPG venture Super Mario RPG: Legend of the Seven Stars Bowser was also present, as well as in Paper Mario: The Thousand-Year Door and Super Paper Mario (however, in The Thousand-Year Door his playable segments were very short, and Super Paper Mario is often considered more of a platformer). and the Mario Bros., similar to how they could with the babies in Partners in Time. As of yet it does not appear that they fight together.

Other non player characters include the likes of Princess Peach, Toadsworth, and various other characters whose names have yet to be confirmed. Enlarged Toads have appeared in various trailers and images due to a dangerous sickness, The Metakoro Disease. No word yet if previous characters from the series will make a return, other than Fawful, who was revealed in some Japanese official artwork. A few of the enemies seem to have green heads and big glasses like Fawful (including a Monty Mole).