New Super Luigi U is a video game directly based on New Super Mario Bros. U. It is described by Satoru Iwata as "Full-Scale DLC similar to the production of full software". This is one of the 3 projects released for The Year of Luigi. It has been released as DLC for New Super Mario Bros. U and as a stand-alone retail title.
The main focus of the game is to guide Luigi to the end of each level. The levels are shorter compared to New Super Mario Bros. U but are also more challenging. Each level has a 100-second limit with no checkpoint available. An additional 100 seconds is rewarded before beginning a boss fight in a tower or castle level (150 seconds is given before an airship boss fight).
Multiplayer mode gives players the option to play as Blue Toad, Yellow Toad and Nabbit, playable for the first time. Mario is excluded from the game. As with New Super Mario Bros U., an additional player can play in boost mode while the rest of the players complete the level. Boost mode allows someone to place boost blocks inside the level through the Wii U GamePad touchscreen.
Luigi - Luigi is the title character and central protagonist of New Super Luigi U. Just like Mario in the previous game, Luigi has to rescue Princess Peach after Bowser manages to throw him and his friends out of her castle. Unlike Mario, Luigi has unique jumping abilities that might be helpful to him. Luigi can jump much higher than Mario and all of the characters. Luigi also has a fluttery jump that allows him to sail through the air much longer than anyone else. When Luigi lands on the ground he tends to slip and slide a bit, though, so caution is necessary around pitfalls and small platforms.
Blue Toad and Yellow Toad - Blue and Yellow Toad return as playable characters for play sessions with more than one player. They are exactly the same as they were in New Super Mario Bros. U.
Nabbit - In New Super Mario Bros. U, Nabbit was essentially a kleptomaniac who players had to chase through levels that they had already beaten. In this game Nabbit has seemingly turned to the side of good and now helps Luigi and his friends save Peach. Nabbit has the ability to run through enemies without getting hurt, which might helpful to young or inexperienced players, though he is still vulnerable to hazardous terrain such as lava lakes or pitfalls. Unlike Luigi and the Toads, Nabbit is not able to use power-ups and any of those that he does get turn into 1-ups. Oddly enough, Nabbit will still appear on the map in single player mode as a thief you have the option to chase through numerous levels.