Thing is how would it work? The game world would have to be constantly running since one player can't 3x across the map speeding the game up while the other player is travelling at normal speed unless one player controlled time which would suck. Or...the game world would constantly have to be running and things would happen whether the player was ready for them or not. Like in normal run speed all the time, which would mean you couldn't 3x across the map or wait in 3x speeds. It would def prove challenging, but honestly this would be only one of the ways you could do it right imo.
Players would really have to work together or against each other along with the ai, since the game world is constantly evolving. Would be fun though. The fact you would have to make quick decisions on the fly without being able to pause the game to think or read what's happening, the game world would just continue to roll regardless.
addition: - Would have to slow time scales/days down quite a bit to balance out since the game world would be constantly rolling.