* {{Blooper}}: The {{superboss}} has an attack where, for one frame, [[https://tcrf.net/Mario_%26_Luigi:_Dream_Team#Glitched_Frame they have leftover debug graphics and an extra floating hand next to their own hand]].
* DevelopmentHell: The unique 2D sprites that greatly resemble 3D models in a 3D world is what caused this game to have a long development cycle (that started right after the third game was released, no less). It got even longer when trying to avert a serious case of AmbidextrousSprite for the bros.
* ExecutiveMeddling: Subverted; the [[https://iwataasks.nintendo.com/interviews/3ds/mario-and-luigi-dream-team/0/2/ Iwata Asks]] reveals Nintendo made numerous suggestions to [=AlphaDream=] similar to ''VideoGame/PaperMarioStickerStar''. However, [=AlphaDream=] did not accept many of the changes, often leading both parties to get annoyed at one another.
* MilestoneCelebration: This game was released as part of the Nintendo-declared "[[Advertising/TheYearOfLuigi Year of Luigi]]", celebrating the 30th anniversary of Luigi's debut in ''VideoGame/MarioBros''. In an unintentional example, the game is this for the VideoGame/MarioAndLuigi series, as this game was released in 2013, ten years after ''VideoGame/MarioAndLuigiSuperstarSaga'' was released.
* WhatCouldHaveBeen:
** The giant battles were originally supposed to feature the same SpritePolygonMix as the rest of the game. But the team found that this wouldn't mesh too well with the new mechanics they wanted to add, requiring them to hand them over to a separate company (Creator/GoodFeel) to finish up.
** The Ice Flower, Yoo Who Cannon and Jump Helmet were going to return, but the Ice Flower was apparently scrapped early on, given only its graphics can be found. Yoo Who Cannon is largely complete, missing only the necessary sprites for the cannons. Jump Helmet is fully coded with the brand new graphics and it would have involved the camera behind the Mario Bros as they ran and bounced from the foreground to the enemies in the background. It was most likely scrapped because it involves using both screens of the 3DS whereas battles only utilize the top screen.
* WhyFandomCantHaveNiceThings: Because of a bug in the original version of the game, [[http://www.nintendolife.com/news/2014/09/mario_and_luigi_dream_team_bug_allows_miiverse_image_posting_shenanigans people could post any saved image]] from the Nintendo 3DS Camera or the Internet Browser to the Mario & Luigi: Dream Team community. Naturally, [[VideoGamePerversityPotential everyone started abusing it]], leading to the ability to post screenshots in the game's Miiverse community to be revoked on September 15, 2014. The ability was eventually restored, but only after a mandatory update patching the exploit.
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