The Legend of Zelda: Skyward Sword is almost 10 years old, originally launching for Nintendo Wii in November 2011. The game was released five years after the last home console entry, The Legend of Zelda: Twilight Princess, and we wouldn’t get the next home console release, The Legend of Zelda: Breath of the Wild, for almost six years--though we did get some other Zelda games along the way like A Link Between Worlds, so it wasn’t completely empty.
The Wii is an SD console with games outputting at 480p, so despite the PS3 and Xbox 360 being around and HD being a thing in 2011, Skyward Sword was only ever seen in SD before now. You’ll also notice in this comparison video that the Switch version is running a lot more smoothly in comparison to the original Wii version. On Wii, Skyward Sword runs at 30fps while the Switch version looks to be running at 60fps.
The Wind Waker and Twilight Princess both got the HD treatment back on Wii U, so it was only a matter of time for Skyward Sword to get the same treatment. The Legend of Zelda: Skyward Sword HD releases on Nintendo Switch on July 16 with newly added button controls as the original version only had motion controls.