Kontext can also take obscure video game sprites and basically "remix" them, creating immediately recognizable yet fundamentally different versions of the same. Here's a random alien stone from Marathon 2: Durandal, and a few effortless variants. Wish I didn't have to go to bed, I have a feeling that with some careful tweaking and some throwaway outputs, this will be good enough to create sprite sheets with almost no editing outside of color palette and pixel grid correction.