Hyrule Warriors Legends undoubtedly pushes the 3DS hardware's capabilities, as is clear from its decent performance on New 3DS but chugging framerate on older models. It should serve as no surprise, then, that it's a single player experience on the portable; considering the performance drop on Wii U with local co-op, it's to be expected that the feature is absent in this handheld port.
Koei Tecmo does show, in its latest video showcase, one way to play this game with others; it's a method that fans of Awesome Games Done Quick will appreciate. Sit next to a buddy and play the same level, and whoever finishes first 'wins'.
That's the formula for the video, and at the very least it gives us another look at how the game runs on New 3DS.