Boss challenge modes have become a staple for Japanese action-RPGs such as Castlevania and most certainly extends the life and challenge of such games. Though Zelda has yet to adopt this type of gameplay, until the upcoming 3DS remake of Ocarina of Time. This will be the first time the icon title will be updated or changed in any way since it’s release for the N64 way back in 1998.
It has not yet been confirmed whether you need to actually beat all the bosses in the game to unlock the mode, but it is known that it will not be available at the start. It would nice to practice up on Queen Gohma, the Twinrova sisters, Bongo Bongo or Ganon before starting out on the adventure.
Anything added to an already amazing game is a good idea in my eyes, so long as such additions don’t cause new glitches or bugs in normal gameplay.