I'm Irish so I have a very poor understanding of the sport. I learned to play Madden at one point but had forgotten everything a week later.
Mutant League Football was brilliant fun; particularly in 2-player. Neither my brother and I understood what we were doing very well but decapitations, bottomless pits and killing the referee were just the kind of thing we could comprehend.
A sequel would definately grab peoples attention, Especially the Europeans and the Japanese.