When Flappy Bird became a huge hit, many were quick to point out that the green tubes in the game bore a strong resmblance to those made famous by the Mario games. It's no surprise that someone hacked Super Mario World, Nintendo's Super Nintendo launch title, into Flappy Bird.

What's a little surprising is that someone managed to hack the game, by hand, and post the video to YouTube.

A little explanation: It's possible to inject code into Super Mario World by manipulating controller inputs precisely when on the correct screens. This actually modifies the assembly language that the game runs on the Super Nintendo, and it's frequently been used to accomplish tricks like warping to the end of the game.

However, when it's used to create entirely new game experiences within Super Mario World, it's generally done with automated tools.

The video above, however, was created with human hands. For further explanation -- and full credits for the people who made this possible -- you simply have to watch it.