“Celebrating the 35th Anniversary since the release of the original Legend of Zelda on the Famicom Disk System on February 21st, 1986; and continuing over from the Zelda II Redux hack, The Legend of Zelda Redux (or Zelda 1 Redux) aims to tackle some of the odd designs and programming decisions from the original NES classic to revitalize and give new life to the beloved and cherished classic.
This hack tries to address a lot of points to make the game fit with the rest of the series (and Zelda 2 Redux) by doing some rebalancing and QoL changes, and also some visual flare into the game, without compromising the original game’s design.”
There is also this if you want a complete overhaul of the graphics.