Mario & Luigi: Partners in Time /NDS

When Princess Peach disappears into the past in Professor E. Gadd's time machine, MarioTM and Luigi travel back in time in hot pursuit, only to come face-to-face with baby versions of themselves, the princess and Bowser.
Threatened by an evil race of aliens known only as the Shroobs, they must team up with their younger selves and travel back and forth through time to save the princess and her kingdom.
Explore the many regions, working with both sets of bros. to jump gaps, solve puzzles and battle enemies. As players explore, they will level-up the characters by using timed button presses to defeat enemies and gain experience points.
Players frequently will have to split up the pairs of bros. to solve puzzles, oftentimes exploring both screens on the DS. In battle, they'll use items and both sets of bros. to dodge enemy attacks and deal their own damage.