So...the new Smash Bros for Wii U is awesome. Unfortunately, not all the stages are great and it's missing a lot of those retro stages we love so much. Thankfully the internet is a thing. This guy really went to the trouble of making these as painstakingly perfect as possible. He says he's going to share them once the feature gets patched, but if you just can't wait here's the instructions:

I tried to make Corneria, but it's not nearly as good as his, and I worked on mine for an hour. I'll prolly re-do it using the instructions. P.S. hit x on your controller to turn on the grid, it makes this way easier.

If anyone finds something similar for 3DS stages, I'd be much obliged.