I saw that suggestion of "pyramid" chess, and posted this because I think it's different. Well, not so much different, but different, in some ways.
Instead of defending your crown against who is in the level under, you have to defending your position against everybody that is in a lower position, not only a level. You don't have any level at all, only a kind of queue, and everybody has a position in that queue.
You can even make a "king of the hill" a default to all players. I mean, when you subscribe to TfC, you get the last position, and is informed of that; when you are searching for opponents, if you choose someone that has a better position than you, you will have an option to play a "King of the Hill" game (in the case the challenged one is not defending his position with more than a certain number of challengers), where you will get the black team and the defender, the white, and your position will be changed by the result if you win.
Obviously, if you don't play KotH games, then your position will change as a result of newcomers going up the "hill".
There's a point that is not clear to me: what happens if you are challenged and loose, and, at the same time challenges someone, and wins. You will lost a position for the challenger, but what position, the new one you get when you win the game as challenger, or the one that you lost as defender? Maybe it will become more easy to program if you allow that all palyers can be playing only one KotH game at a time.