"Mario & Luigi: Dream Team was my favorite of the games I saw at the 3DS preview event this Wednesday. Thankfully, it also had the longest demo I've ever played at an event.
"The game is set on the seemingly abandoned Pi'illo island, where soon after arriving for a vacation with the Mario Bros., Princess Peach disappears. (Of course.) The game moves between two separate areas of gameplay: Pi'illo Island locations with traditional Mario & Luigi gameplay, and Luigi's dream world where Mario fights alone but is granted special powers and assistance by Luigi's imagination, or "Luigination.""