The second game in the Mario & Luigi RPG series, released in 2005 for the Nintendo DS. The Japanese name is Mario and Luigi RPG 2x2.The game changes a few game mechanics from the first one, and teams the brothers up with their time-travelling baby selves (who otherwise appeared in the Yoshi's Island games) using hilariously bad time travel "logic". Princess Peach travels to the past and is promptly kidnapped when the Mushroom Kingdom of the past is invaded by the alien Shroobs. Our Heroes go into the past to find her and have to collect the crystal shards that formed the Cobalt Star that was used to power the time machine in the first place while teaming up with their infant selves as well. Other than that, it's still pretty much the same game with witty dialogue and funny animations and some limited usage of the DS's features. The move-sets were altered to give each pair (bros and babies) unique items and moves, such as only the babies using hammers, and the Bros. moves in battle have been replaced by Bros. items instead.
They get healed during the dissolving of most of the remaining Shroobs
Back from the Dead: Interestingly, Fawful returns in this game as a shopkeeper despite apparently dying in Superstar Saga.
Who said he was dead? He was just thrown out of Bowser's Castle... thousands of feet in the air...
Bad Boss: Elder Princess Shroob frequently outright kills her henchmen during her (two, unless you count Shrower) battles against the Mario Brothers...
Which makes you wonder why they and her sister didn't do anything when she split into six.
Actually, the Shroobs spend the entire game trying to stop the Mario Bros. from reassembling the Colbalt Star. It seems they weren't big fans of the Elder Princess Shroob.
Balloon Belly: Baby Mario can get like this by guzzling from a water source.
Bandit Mook: Dark Boos, who steal an item from the Bros should their attack connect. They flee the next turn after they steal an item.
Evil Counterpart: The Shroobs often act like this to the Toads, even having an enemy ingame known as the Shroobsworth.
Evil Detecting Baby: When Princess Shroob arrives in the Mushroom Kingdom disguised as Princess Peach, Baby Peach is seemingly the only one to recognize her as she cries right in front of her.
Also, Baby Luigi. He cries when he sees the ghost of the Cobalt Star which is really the Elder Princess Shroob's spirit or ghost.
Evil Twin: Princess Shroob has a very strikingly similar outfit to Princess Peach. Also, Elder Princess Shroob seems far more savage in comparision to her sister.
Exotic Entree: When baby Bowser is choking on stolen cookies, he is offered milk from Kamek, who insists it's from an evil cow.
Fridge Logic: In Partners In Time, apparently Mario was content to let the Shroobs destroy the past world as long as Peach is safe. Also, why would the old Toadsworth not recognize the young Toadworth, since he himself should've been able to remember that, as he was like an adult then?
Mood Whiplash: For most of the game you are treated to a cheerful, upbeat soundtrack, and then you get to the final boss and the tone of the music becomes dramatic.
The destroyed Toad Town section of the game is immediately followed by the celestial peace of Star Hill.
inverse: when you first arrive in the past, the first area has a bouncy, lively rendition of the original Mario theme, but then you get to Holli Jolli village, in a similar state to Toad Town with an equally depressing track; a sad version of "Jingle Bells".
My Future Self and Me: The gameplay hook for this game has the adult and infant Mario Bros. teaming up inside and outside battle.
Having both generations of Bros. together in battle lets you use attacks and Bros. Items in new ways, such as double jumps and fireballs that can target air enemies.
Nice Job Breaking It, Hero: Assembling the Cobalt Star, which takes 95% of the game, undoes everything Peach sought to avoid from the start of the game and unleashes the Elder Princess Shroob
Point of No Return: Used and subverted : The fight against the Shroob Mothership is the point of no return, but Stuffwell warns you about it. Even better, after you pass the PONR, he gives you the possibility to go back to before the fight, asking you every time you hit a save point.
Portal To The Past: They conveniently start appearing all over Peach's Castle after E. Gadd's Time Machine returns useless.
Post Climax Confrontation: When Mario, Luigi, and the babies return to the present after defeating both Shroob Princesses along with the rest of the Shroobs, what's left of the Elder Princess Shroob possesses Bowser for one last battle.
Speaking Simlish: Everyone. The Bros' version sounds vaguely Italian, with a few recognizable words; the Shroobs are entirely tonal.
Sugar Apocalypse: What happens to Toad Town and Hollijolli Village. The latter is probably more unsettling, it happens right as Mario and Luigi are watching, and right during Christmas.
Timey Wimey Ball: It's probably best not to analyze this at all, as the time travel doesn't even try to make sense.
Considering the series made little sense, anyway.....
I thought they just traveled back and forth, between 2 different time periods, like Ocarina of Time?
There's a great timey-wimey scene that combines Meanwhile, in the Future with Ripple-Effect-Proof Memory — The Bros give younger Professor E. Gadd a Eureka Moment, and we cut to older Professor Gadd, who is having the idea at the same time, and is aware that it's because his memory is changing.
Underground Monkey: Many enemies are merely Shroob versions of standard Mario enemies. One good example is the Tanoomba, which gets a Shroob variant in the final dungeon.
What Happened to the Mouse?: In the ending, when the Shroobs and their creations are eradicated, we don't see what (if anything) happens to Yoob. (We also don't see Toadbert or Toadiko returning to the present, but since Toadbert appears looking the same in the next game, it's likely that Toadiko made it back as well.)
Wingdinglish: How the Shroob language is presented.
Villainous Breakdown: Given what a short temper Princess Shroob has, it's not surprising that she eventually goes berserk following the destruction of her Shroob mothership...