Mario and Luigi have been through a lot together. They've defied death in numerous dungeons, escaped a plumber barbecue in many lava lands, and – in one of Mario's most daring adventures – beat a giant penguin in an ice race. Oversized Goombas and Koopa Troopas are no match for this duo. Not even a clogged toilet can stop them!

In Partners in Time, the we-couldn't-wait-for-it sequel to the Game Boy Advance adventure that was spun off the Paper Mario series (Mario & Luigi), the plumber brothers are forced to go back in time and meet up with younger versions of themselves. "Teen Mario, alright!" No gamers, not teen Mario: Toddler Mario. Baby Mario to be exact. He jumps, hits blocks, and can squash Goombas just the way he always has. He crawls too, and has the uncontrollable urge to whine.

Baby Mario was first introduced for a more colorful game that would appeal to youngsters, but his purpose in this adventure should be much more satisfying to long-time fans: he's to make us laugh. Baby Mario doesn't leave the side of his baby brother, Baby Luigi, and it's love at first dribble the first time he comes in contact with Baby Peach. Where there's Baby Peach there's Baby – hold onto your shells for this one – Baby Bowser! Alien mushroom people are taking over the world (they're called Shroobs), and in less than a day the babies must mature and fight a battle that their adult counterparts can't fight alone.

I'd be lying if I said this didn't sound like a concept born out of a fan fiction forum. Nonetheless it works, though not as effectively as the first game and nowhere near as funny as Paper Mario, the adult/baby combo are pretty hilarious at times and have paved the way for what Mario fans desire the most: new gameplay.

Mario & Luigi was unique in that the two characters could be controlled simultaneously. This was done by applying one jump button (A and B) to each character. Their other moves were linked outside of battle; when Mario moved Luigi followed from behind. This technique was clever and effective. I loved how they implemented individual jumping and how you had to cross platforms by hitting both buttons at the same time. Technically this was a very simple addition, but it didn't feel that way. It added a lot to the experience and made you believe you were playing a new Mario game, not just another Mario sequel.

Partners in Time follows suit with a few changes: the babies are not linked to the adults! Only when piggybacking can the babies move with the adults. When crawling the babies jump with the X and Y buttons. Press the A or B buttons and the game immediately switches to the adults. It sounds like a lot of unnecessary switching, but it won't take you 10 minutes to figure it out. In-game tutorials are present and may be ignored if you know (or think you know) what you're doing.

I didn't need the game to teach me how to jump, however, the information was helpful in learning the new team and duo attacks. Originally it was possible to inflict a few extra points of damage by hitting the jump button just before Mario or Luigi landed on the enemy. With the babies riding on their backs, Mario and Luigi may now inflict even more damage by first hitting the babies' jump buttons (X or Y) just before grown up Mario or Luigi lands, then hit the other jump button to dish out more damage.

Things get even crazier when you start bouncing shells off your opponents. The shell bounces back and forth between Mario and Luigi. If the babies are on board, one of them will ride on top of the shell and hit the enemy with extra force every time the shell strikes it. To unleash that extra force you must hit the baby's jump button as the shell hits! The shell increases in speed with each hit.

Essentially it's a timed combination that goes something like A-Y-B-Y-A-Y-B-Y-A and so on until Mario or Luigi misses kicking the shell back at their opponent. I hate icon games where you have to hit the right button exactly when its icon appears on screen - this is nothing like that. In this game everything is based on the timing of the visual. You have to follow the action and play accordingly. Anyone can do it, but you will have to practice.

The utilization of the Nintendo DS's six-button layout isn't the only change or the only attempt at innovation. Partners in Time uses the bottom screen for most gameplay scenarios, but the top screen is not ignored. During battle it can give information about your enemies, indicating the plans of a sneak attack, or showing what the enemy plans to do next (exact details are a surprise, but I'm sure you've seen the first screenshots Nintendo released. They were quite revealing). Outside of battle the top screen shows valuable map details. Your exact location can be determined at any time just by looking up. Need a specific item? Looking for a save book? Check the map – everything's presented with a clear visual.

When Baby Mario and Baby Luigi are separated from the adults (which happens often and is necessary in solving many of the puzzles), they are likely to enter an area that is not visible on the bottom screen. Thus you control them from the top screen. Instead of having to endure a jerky screen that hops back and forth between characters, the top screen stays with the babies; the bottom screen stays with the adults. Pressing the babies or adults' corresponding buttons is what determines which characters will move since you cannot control all four at once in these scenarios.

Gameplay: 9.2
The best Mario game since  … Mario Kart DS! This has been a great year for Mario, he’s had several great games, one after the other. Mario & Luigi: Partners in Time is a semi-innovative expansion of the first game, an RPG that blended together the world of Mario and role-playing games perfectly. The new combo and duo attacks are very inspired. You can tell that each developer was a fan of the series, taking all things Mario into account before pursuing new options. The new additions are great, the baby/adult Mario and Luigi gameplay is awesome, and the enemies, both old and new, will put a smile on your face.

Graphics: 8.0
Refined and newly animated, Partners in Time expands on the cartoony art style of the first game with a number of tweaks and touches. Players will be impressed by 2D animations, especially during battle. A Shy Guy and Bullet Bill combo – very clever. The colossal boss battles are unforgettable. The goofy look on Mario and Luigi’s faces is a bit creepy, but at least they don’t look like babies (except when they are babies).

Sound: 8.5
Classic Mario tunes remixed for another adventure. The simple (and sometimes annoying) voice-overs from the GBA version of Super Mario Bros. 2 make their return, as do the series’ unforgettable sound effects. Many of them have never been used in the same game before!

Difficulty: Easy/Medium
Mastering the unique control system is more of a challenge than the enemies. I wouldn’t call this an easy game, but there are few moments that elicit frustration and hardly any times where you’ll say, “Wow, I can’t believe I completed this.”

Concept: 8.0
I’m a little disappointed with the story – I expected to be laughing hard for hours, and looked forward to talking about those scenes for months to come. “Did you see the part where Mario ___? Or when Luigi ____? Hilarious!” That didn’t happen. Partners in Time’s dialogue isn’t as sharp as the first, nor is it as clever as Paper Mario.

This flaw was almost entirely forgiven once the game began and I got to control not only Mario and Luigi but their baby counterparts as well. That idea, though childish in concept, was an entry point for innovation. The puzzles are clever and are far more interesting than the story. There isn’t a Mario fan on the planet that won’t get addicted to the battles, which are better and more expansive than the original.

Overall: 9.0
Mario & Luigi: Partners in Time carries on the Nintendo tradition of advancing the Mario series in new and unique ways. Though not as innovative or as funny as the first, no fan will be able to put the game down, nor will fans be able to finish it without feeling excited and satisfied. The overall experience is an unforgettable one, with excellent gameplay, clever puzzles, and some of the greatest scenarios Mario has ever been a part of. Unfortunately for the Big N they are now obligated to include all four characters in the next Mario & Luigi adventure because we won't accept anything less. (Was that not threatening enough? Maybe if I say it in my deep Bowser voice they’ll listen. Keep your fingers crossed.)