EDIT! I just saw another idea identical to this. The other was posted first. I didn't steal it from him, but he did have the idea first. The option to throw the grif/oddball had me very excited. My initial goal for it was to create a football game, but I realized how impossible that was very quickly. However I have come up with a possible idea for a rugby/ ultimate Frisbee style game. Here's how it works. The gametype is grifball on the court. The goals would be turned into endzones (not sure if possible). All players are 100% invincible. They have regular speed and thruster packs with unlimited use. The ball carrier has no AA use, is as slow as possible, can jump higher than the other players, but isn't invincible (he would probably be 3-4 hammer hits = death). The ball carrier is so slow because the game relies on teamwork and passing. The whole idea is that a score can really only be achieved through teamwork. The players are invincible because the ball will be in the air so often. If they want to take the ball they must intercept it instead of stealing it from the carrier. I'll probably be putting this into action this evening or this week. Send Ph33no a friend request if you're interested.
You can make him invincible still, and make him have 0% movement. That way if he has the ball he/she can't move like in Ultimate Frisbee. I think the grav hammer affects the ball, so you could make that the only weapon so it could be intercepted or knocked out of line of motion with that, you know? Very interested in this, cause I tried the Rugby gametype but it ended up just like GrifBall. But I just thought of the 0 movement thing, so let me know.
Already got a game like that. I took it from a youtube video here https://www.youtube.com/watch?v=VBqsLWRiRss Works pretty well. I'll send you a friend request and maybe we could try out something.