This is an idea that I've been thinking about for a long time. I had a lot of different ideas about how to approach it, but when the theme of "sports" was announced for this competition, I decided I would take a crack at it as a simple fighting game based on mixed martial arts. In my opinion, fighting is the purest and oldest of all sports.
I'm planning to use a skeletal animation system which I foresee having certain advantages, but also certain disadvantages (such as making it difficult to animate like spinning around). We'll see how it pans out. I'm really most excited about all the juicy details, like dynamic blood dripping from noses, basic cloth physics, and that kind of thing. I also have some ideas about a dynamic soundtrack that layers on instruments as the intensity of the fight increases. I'm just gonna start very basic, and if it ends up being promising, I would like to expand into a full size project, once I've finished all my current commitments.
The most difficult part will be dealing with grappling and submissions, since that's the area where I have least personal experience. I did Tae Kwon Do for many years so I think crafting the striking part will be pretty easy. It might be useful for me to check out UFC Undisputed or that EA MMA game to see how they handle it. I'am also looking at games like Nidhogg, Hotline Miami, and of course regular 2D fighting games. If you have any ideas, I'd like to hear them.