Takashi Tekuza revealed in an interview on the Nintendo.co.jp website, that Super Mario Bros. 3 was originally planned to have an overhead perspective rather than a horizontal one. The title, that debuted on the NES, ended up in a horizontal view because they couldn’t make their original plan work. Check out the snippet of the interview with Tezuka and Miyamoto below:
What sorts of things did you have trouble getting right?
Tezuka: When we first began development, we wanted the game to have an overhead perspective, rather than a horizontal one.
So instead of having a horizontal view of the game like in Super Mario Bros, you wanted something like an isometric view.
Tezuka: That’s right. But, we just couldn’t make it work.
Miyamoto: He said “I want the game to be viewed from a little bit above.” But having a clear indication of where you’re going to land after jumping was a key part of the original Super Mario. Viewing everything from above made it very difficult to tell how far you were from the ground, so I told Mr. Tezuka “This will take forever.”
Tezuka: …He did (dry laugh). In fact, there are still remnants of the top-down view in the final game, from before we switched to the horizontal view…
Miyamoto: Yes, there are.
For example, things like the black and white checkered floor?
Tezuka: That’s right.
However, Paper Mario: Colour Splash does have some gameplay in a overhead view, so the idea wasn’t completely forgotten about in the long run. You can take a look below: