As I can understand, by “oxygen compounds” you mean CO2.
Actually it would be cool to have it in the game, but I don’t really see how sulfur photosynthesisers can become multicellular, and even more than that, hunters of some kind. To answer this question we need to know, why there is no active plants on Earth and what conditions are preventing it from happening.
I heard that plants are just way slower in producing energy therefore they can not be active. May be I am wrong though.