You've got some strong character designs here! I could definitely see them interacting in an animated environment. I also really like the way you broke convention by making Medusa a love interest when she's normally a baddie; that's an innovation I would definitely like to see more of in animation today...it would be interesting to see what other role reversals people could come up with!
I like Polyphemus the best, I think it's those bendy limbs of his