I bought Shovel Knight (3DS) off the eShop. I was really conflicted over whether I should get it on the Wii U and benefit from big screen play or on the 3DS and be able to play it on the go, and I wasn't going to buy a $15 game twice (where's my cross-buy system, Nintendo?).
After having played the first level, I'm glad I got it on the 3DS. They really put some effort into the 3D effect, to the point where I noticed up to 4 or 5 layers in cut scenes, and at least 3 or 4 in-game. It's really quite a site to behold on such a NES-looking game.