The Year of Luigi's main events are drawing to a close with Nintendo's first real foray into first-party DLC with New Super Luigi U, a downloadable expansion to the original New Super Mario Bros. U. It's truly an expansion, utilizing all the original game's sprites and basic level designs, with no true new additions (I'm really miffed they didn't even pallete swap Peach to be Daisy to be saved). What you get is a fleshing out of the original levels catering to the hardcore gamer. Think Mario meets Bullet-Hell shooter, and you've got Super Luigi U. All the regular secrets, hidden areas, and multiplayer mayhem you've come to expect from this generation's Mario games combined with the artistic precision required to dodge each enemy and projectile. Some will find their opinion of a brand-new game with brand-new challenges, others will see a rehash of old stuff with no new content worth any price.
If anything is to be criticized about the game, it is that the precision required deters you from the exploration inherent in titles like this. Unless you're lucky, you'll find yourself going through the level three times to acquire all three Star Coins. To some, a lesson in redundancy, to others, replay value.
Luigi's physics in this game differ from Mario's greatly, feeling more like the floaty/slippy Luigi you know in other games. This is partially compensated by some coin lines that guide your jumps, but it mostly just ups the difficulty of the timing of the jumps. Unlike most Mario games, this puts Luigi on rails in a way: there really is only one way to truly get through the game. Some will relish the patterns and attempt at perfect runs, others will feel as if it is a hackneyed attempt at making levels with no replay value.
Nabbit is the replacement fourth character, the little purple bunny dude who likes to steal power-ups. While he can't use them, he'll net a 1-up for every one he makes it through the level with. He also won't die from basic hits from enemies, but pits will still nab a life away from him. Precision jumping is necessary to play as Nabbit just as it is for the other characters, but I feel Nabbit is there primarily to allow your younger child/sibling to get in on the fun without the frustration. Just as in NSMBU, there is fun to be had in multiplayer, but the collision between characters and precision needed for jumps means you will die a lot, and this is even more prevalent in Luigi U. Nabbit lets a younger gamer play a "me-too" session with you as you sweat your way through the levels.
You won't find anything "new" in this game. The levels are shorter due to the time limit, but all have the general flair of the original with added difficulty not seen since the original Japanese Mario 2. The prime power ups are only attainable whilst risking your life to obtain them. Sometimes the game tries to hold your hand like NSMBU by offering you free "bubbled" power ups, but they tend to only be mushrooms, and they come at very opportune times, usually to eliminate frustration that would come from an instant-death following a harrowing run.
As I said in the beginning, New Super Luigi U will only cater to a specific crowd, but those people will abolutely love it. Pick the game up if you love challenges, precision gaming, or Mario in general. Avoid it if you hate defeat, desire freedom to do exactly as you please, or expect "more" out of this game. Personally, I'm in love with this, and will probably defeat Bowser in Luigi's game before I do so in Mario's.
New Super Luigi U can be picked up via DLC for New Super Mario Bros. U right now for $20, or you can wait a bit and get a hard copy at a higher price, but many I know want it for the limited collectability of it (as well as the nifty green case). If you have the room on your hard drive and a copy of Mario U right now, there's no real excuse not to pick this up today!