Here's some "official artwork" for a fake game idea I have called Super Mario Mania. Taking obvious cues from Sonic Mania, Mario Mania is designed to take from the SNES to N64 era of Mario design and see what a 2D platformer would look like if made around then.
Directly translating Sonic Mania's fanservice romp to Mario doesn't exactly work when there aren't a lot of distinctly memorable locales pre-Mario 64, so it's more about what a fresh game would look like than a celebration game.
More stuff, including pixel art, will be coming in the next few updates. And no, it's not a real game, nor do I have any intention of it being one.