Nintendo couldn't fire off an ace

Tennis for the NES has already been released via the Wii Shop Channel as a Virtual Console game, but at one point, it was also in the process of being brought over to the 3DS as part of the 3D Classics range. The latest Iwata Asks centres on the Nintendo eShop and reveals why that re-release never came to fruition.

Takao Nakano, 3D Classics director spoke to Nintendo's CEO and president Satoru Iwata about Tennis' depth perception and how it didn't feel right when displayed on the 3DS's stereoscopic screen:

One game that didn't go well was Tennis for the Famicom. The tennis court originally in the background had perspective, so I thought we could simply shift it to 3D. But we had originally created that screen to have a three-dimensional effect in 2D, so in real 3D imaging, it wasn't very surprising. I thought, "That's totally normal!" (laughs)

Eventually, the workload proved too much as the low payoff ate up too much time and effort, resulting in the project being abandoned:

And a programming problem arose after changing the collision detection for the ball and racket from a plane to a 3D field. It took as much work as making a tennis game from scratch. If there would be the surprise of seeing it become 3D, we might want to make it, but we had to conclude that the resultant value would not be worth our hard work, so we scrapped it.

[source nintendo.co.uk]