I'll try to explain this the best I can, maybe add some badly-drawn (and scannerless) visual aids sometime.
The gamemode is meant to be hosted on a multiplayer server, although could probably be played alone if you wanted to.
When the game begins, players are split into groups of 2 (if there is an odd number of players, a random player competes against a bot), and set in front of 2 different tracks on which they must race.
The catch is that there's no vehicles. So, how do you make this interesting?
Obstacles.
The gamemode I thought of would essentially be an obstacle course; same (duplicated) track for each group, 2 different players. The goal is what you'd expect; get to the finish while avoiding an assortment of obstacles that block your way to the finish line.
The obstacles could range from wooden bridges with weak rungs (should be subtly hinted at) to swimming through an underground maze. The possibilities are endless.
So who would want to see this happen and where can I get a good coder?