Mario & Luigi: Dream Team
Mario & Luigi: Dream Team
In the UK and Australia, the game is changed to add the "Bros." at the end of the title.

While no official reason was given, the trademark for the name "Dream Team" was filed in the UK in 2010, and was still valid until the games release. It's possible Nintendo added the "Bros." at the end to avoid any legal issues with the trademark.
There are 3 unused attacks for Mario and Luigi present in the games files, Ice flower, Yoo who cannon, and Jump helmet.
Contributed by MeleeWaluigi
The developers considered making Bowser a playable character early on in the planning but scrapped the idea to keep the focus on Mario and Luigi.
Contributed by The_Maxious
A frame of Bowser Jr. slamming his hammer is graphically faulty.
Contributed by Dazz
Touching Luigi's cap on the title screen will allow the player to mess around with his mustache, nose, and cap, as they would during game play. Each action made to Luigi will alter the top screen.
Contributed by gamerofgames