Not quite roles, but I did originally intend to have both physical and gameplay related characteristics changed through breeding, and get increasingly crazy with each subsequent generation (to the point where you'd have weird, lovecraftian baerats with spider legs running around, and things like that). So for example, one baerat might be very speedy, causing it to pick up more cheese, but also making it burn through its hunger bar faster. But yeah, I had to cut like 90% of what I planned. Not sure yet if I'll pick it up again. Thanks for the comment!