Nintendo was originally planning to include Zapper support in The Legend of Zelda

Here's an excerpt from that interview...

Miyamoto: During the early planning stages for the first game, we were discussing whether or not to use the Zapper, but there were a lot of people who didn’t have one. If we’d had the memory for it, though, we might’ve done it.

This might be an old interview, but it's definitely worth checking out. I think the focus on Link to the Past makes it for a great read.

Check it out here