https://www.youtube.com/watch?v=vJpMZ0R89kU
I wondered to myself............... this is animation without being real animation. It is simply an image with another layer sliding across it.
I would think that dragging one layer over an image isn't too computationally taxing, so this could be a really cool visual trick to pull off with older consoles.
Here is a spinning cube running on the SNES.

layer 1

layer 2

The only thing is, on the NES you don't have any layers other than the sprite layer. So the animation could only be as big as a square grouping of all of the sprites. The sprites themselves are the black bars and are 7 pixels thick with 1 pixel being transparent.
So I'm proposing this to the NES community. Can anyone make a small image that animates in this fashion on the NES? How big could you make the image? Essentially its just an image with black sprites scrolling across it.
Making the animation is a little tricky, but basically take photoshop (or any other program). Find or create your own animation. This typically works best for 8 frames of animation. The sprite tile is 8 pixels wide with 1 being transparent so to get the number of frames its 8/1 = 8 frames. So once you have your image, you get the black bars and the image in photoshop. You look at the 1st frame of animation and delete the black bars portion of the image, then slide the black bars over 1 pixel. Then you take the 2nd frame of animation and delete the black bar sections on that image and so on. So you are taking a slice out of each animation frame there is and putting it all into one single image.