More than the mailman himself, what I really love about this is how well you portrayed the landscape of Ocarina of Time. Instead of N64 graphics, we now get to see it as it was intended to be seen and originally imagined in awesome painting form. The mountain/windmill/entrance to Kakariko reminds me a bit of Okami; have you ever played? It looks much more realistic than it does in the game, a great visual aid for one's imagination.
The use of colors here is absolutely awesome - I always have trouble with my color picking, but you do it extremely well! I like how bright and happy it is - complete with the awesome carefree mailman running through the fields happy as you please.
And of course, who can't dig your awesome mailman? <3