Wow, super impressive work, especially considering the limitations! Though, I for one am drawn to Pixel Art because the restrictions force ones-self to get resourceful about making the most of what's available. Getting the color resolution you have there on the SNES is making me see stars! It's reminding me of this one dude's project where he got Super Mario for the SNES running on an unmodified NES. (If you guys haven't seen that, it's over here-- super fascinating, too!)

And I second what Sersch mentioned, because for some reason I never got any impression that Nintendo hired contractors; I, too, was always under the impression that they only did stuff in-house, so whenever I'd hear stories like the Doki Doki Panic reskin I thought it was a very rare exception that they'd make use of outsider assets. (Let's forget the CD-I ever happened.) Though, after hearing the behind the scenes of BOTW where they mentioned having another team flesh out the bulk of the world's terrain, it's becoming more and more apparent. It's so weird how it never occurred to me until it was pointed out, haha! I suppose everyone (yourself included, Billzilla!) does such a great job of staying on model that it's easy to imagine all the assets being handled by a super small team.