Yup, you are right, totally niche stuff but its looks amazing :) I know ofc not every of them looking cool on pixel art graphics. Maybe some shipwrecks/debris, tiny abandoned lifeboat, Blitzar (looking cool, like a space amoeba), Wolf-Rayet Star, Hypernova, anything unsual.
Me and my brother working on a lightweight 4X space strategy game, but we are moving slowly on development.