Mario & Luigi: Partners in Time is the second entry in Nintendo's fledgling role-playing game franchise starring the brothers Mario. The series began with quite a bang in 2003 with Mario & Luigi: Superstar Saga, a polished action RPG for the Game Boy Advance. For the next entry in the series, Nintendo and developer Alpha Dream have moved the sequel to the DS, have done some tweaking to the winning formula introduced in Superstar Saga, and have taken advantage of some of the bells and whistles offered by the dual-screened hardware. The end result of all this work is a sequel that maintains the same level of quality as its predecessor but falls just a bit short of surpassing it.

Mario and Luigi return to save the Mushroom Kingdom's past and present.

The game's setup puts a new spin on the typical "kingdom and Peach in danger" scenario that anyone who has played a Mario game knows well. This time out you'll once again take control of Mario and Luigi as they set out to save the Mushroom Kingdom and Princess Peach from danger. The threat to all things Peach-y and mushroom-y comes from the darkest reaches of space. An evil race known as the Shroob has decided to look for greener pastures now that its world is no longer the jumping hot spot for life that it used to be. As luck would have it, the villainous fungoids, led by the villainous Princess Shroob, get a look at the Mushroom Kingdom and reckon it would be the perfect place to hold their stuff, hence the conquering. The twist to this setup is that this all takes place in the past. Over the course of the game you'll wind up going between the past and present to deal with the Shroob as they attempt to wreak havoc on both ends of the time stream.

It's a heady challenge to be sure, but you'll get help from a number of different places. You'll find a colorful cast of characters, some of which include the usual Mario suspects, such as Toadsworth and Professor E. Gadd. The good old balding, bespectacled professor also tosses you a bit of extra help in the form of Stuffwell, a sentient suitcase that doubles as a computer and serves as your assistant. You'll find that this luxurious leather companion comes in handy as you find yourself interacting with the past and present versions of the core game cast with astonishing regularity (apparently the Star Trek rules of time travel don't apply here). One notable aspect of the story is the way it deftly avoids the "cute" pitfall that it seemed destined for by the inclusion of Baby Mario and Baby Luigi. While the toddlers are as cute as can be, they're never overdone, which is good to see. The overall tale is well stocked with the requisite zaniness and twists you would expect, but it doesn't gel quite as well as Superstar Saga. The self-referential humor that gave the original game its bite isn't as prevalent, which leaves a serviceable story that, while still funny, is a bit on the bland side.

Who knew child endangerment would pay off so well?

Of course there are still plenty of teeth to be found in Partners in Time's gameplay, which takes the core mechanics from Superstar Saga and tweaks them. If you played the original GBA game, then you should feel right at home when you fire up Partners in Time. Your time will be spent exploring different locales in the Mushroom Kingdom (in both the past and the present), solving puzzles, and uncovering more of the mystery behind the Shroob and their spongy princess. The game uses the basic mechanic of assigning a character to one of the DS's face buttons, with A controlling Mario and B controlling Luigi. The biggest addition to this system is Mario and Luigi's preschool alter egos from the past, who are controllable with the X and Y buttons. While you can control both sets of brothers as a team, with the babies riding piggyback on their adult counterparts, you'll often have to control both pairs independently to overcome the numerous obstacles you'll face. The babies, being considerably smaller, can squeeze into places or even be flung to locales that the older brothers can't reach.

You'll find that each set of brothers feature different abilities. For those keeping score, the adult versions of Mario and Luigi feature a scaled-down set of special moves from the first game. In addition to the pair's running and jumping abilities, you'll be able to interlock the two to form a quickly moving ball or to perform a variation on their propeller spin jump. The babies, on the other hand, must make do with Hammer Bros.-provided hammers, which let them hit switches or burrow underground. You'll also be able to make constructive use of child endangerment by using the older brothers to roll over their younger counterparts, temporarily flattening them to wafflelike proportions, which will let them squeeze into even tighter places or ride gusts of wind. Like the previous entry in the series, Partners in Time will feature agreeable RPG-lite elements and will let you earn experience--from defeating enemies--that you can use to level up and coins that you can use in the shops to buy items, clothing, and badges. The clothing and badge system remains essentially untouched, except that now you can outfit four adventurers. Though the clothes will come in adult and baby sizes, the badges, which offer different bonuses, can be equipped by all.