I am exploring the idea of an open world game with this mechanic. Where you have to progressively climb more trecherous towers to kill more Tyranous kings.
An alternative is a level based one with a central hub (like Doom) + a level editor and ranks like Mario maker
Or perhaps something where you have to keep going higher to more difficult climbs, and somebody holds the world record as the king of the hill (or tower in this case...)
I have some thinking to do...