Ultimate NES Remix is a series of mini-games based on almost every major first party Nintendo game for the Nintendo Entertainment System. Super Mario Bros, The Legend of Zelda, Kid Icarus, Donkey Kong, Metroid, and so many other staples of your 80's childhood are all here. There's even both versions of Super Mario Bros 2 for the anal fan who really has to remind everyone that the US one was just Doki Doki Panic like it even matters anymore.
Each game comes with a set number of challenges. These can range from the basic abilities in the game like defeating a certain number of enemies in Mario 3, or driving without crashing in Excitebike. Depending on how quick you complete the level, you're given a star amount. The more stars earned, the more levels you unlock. These include other stages in this game, a whole new game, or the remix levels.
And the remix levels are where the game really picks up in interest. These stages change the basics of a certain game, from how you have to complete the stage, to the characters being used in it. One level will have you try to make it to the end of a Mario three level while having disorienting clones near you. Another level will have you as Link having to make it up the construction site to save Pauline from Donkey Kong. There is enough variety in the stages that you never know what's coming next.
Also added to this version of NES Remix is Fast Mario Bros, which is pretty self explanatory. It's Mario 1 on fast forward as have to make it through the game with the speed being super fast. This is an interesting mechanic, but I do find it can make certain areas like some of the painful jumps of World 8 an even bigger pain than they already are.
The final major mode is a championship mode. Akin to the legendary Nintendo World Championship cart, the goal is to get through three games with the best score. However, where the original cart was Super Mario Bros, Rad Racer, and Tetris, this time around it's Super Mario Bros, Super Mario Bros 3, and Dr. Mario. Your best score is then put online to compete with other players. Speaking of scores, the game will choose a different challenge every day for you to compete in to try to outrank other players, so that does give incentive for replayability.
In the end, Ultimate NES Remix doesn't really do anything particularly new with the series, but being on a handheld like the 3DS and the variety of games within does make it a worthwhile purchase. Sure, in some ways this feels like a 40 dollar ad for the Nintendo Eshop where all of these games are available (there's even a button that will automatically take you to the Eshop), but if you're looking for fun and varied challenges, and can't get enough NES Nostalgia then I say this is worth the buy.