IGN had a hand in its creation. They didn't 'make' it, but they Produced it. Executively.
It is an April Fool's joke.
Which makes the MGS4 April Fool that much better, since while it's a joke it's also real (with brand new gameplay). This Zelda thing is still pretty impressive though.
Ah ok. Well when I saw that a real production team had made it I thought that it was just going to be an independently made movie.