It could've been better.
First of all, you needed to change the FL Slayer instrument a bit, powerchord mode can't play melodies without making them sound awkward. Second, you just needed a bit of dynamics in your drums; tweak with the velocity a bit, add one or two more instruments, and you'll have a great song. I'd love to see the improved version.
I like the idea here of taking the music from the game and mixing it to make it harder...
But it's not Zelda's Theme.
And the melody is slightly off. I don't know if that was intentional, but I would go back and listen again.
Please contact me if you would like to use this in a project. We can discuss the details.