As it stands, its not a common venture for pixel artists like myself. I have seen it in only two hobbist games: My own Mysterious Islands, and SMW: All-Star Edition. Within the Rom-hack community. BMF's Super Mario Odyssey and Merthack's Super Mario Planet. Another series is the Devious Four Chronicles which I have gotten to know metalgearhunter and Scorpion well.

Any other spritees you came across that can do such a feat.

I can't immediately think of any fangames where every background was custom-made pixel art. On a more general level, my Cheerwine Deluxe games use a lot of photos I've taken myself, although those obviously aren't pixel art.

Some of the backgrounds from my games (like MLVSTF the aurora background) and some backgrounds in Red Scare 2. Also backgrounds in Cops. I sprited by myself.