The Legend of Zelda: Breath of the Wild started as a 2D prototype in the style of the original Zelda on NES. While Nintendo never did anything with that starter set of code, a fan has done his own work to bring a 2D Breath of the Wild to PC.
Creator Winterdrake has made a free demo, entitled Breath of the NES, and uploaded it to itch.io for players to try. "The demo lets you play around in a mini overworld, testing out the gameplay, and discovering tons of fun items," he said in the demo description. "Breath of the NES offers a new adventure in the classic Zelda style, but with smooth animations and a more interactive world!"
The game works with a keyboard or gamepad, and looks to be a pretty cool recreation of the original Zelda's look and feel. It's hard to tie the demo to Breath of the Wild, though, as you don't get to see any of the locations or characters. Hopefully newer versions will have them, as Winterdrake already has done several updates to the demo.
Again, you may want to try this while you can. Nintendo is notorious for protecting its IPs, so despite Winterdrake's attempts at homage, this may fall victim to a cease & desist order.
Check out the videos below. The top one is the demo, the bottom is what Nintendo created and showed off at GDC in March.