[Idea] Double-time Challenge

Half the timer (normal and overtime)

Double the troop speed

Double the troop attack speed

Double the spell speed

Half the spell time

Half the building time

Double the building attack speed

Half the activation timer for all cards (e.g. Golem would be 1.5 seconds not 3)

Double elixir for first minute, quadruple elixir for the rest of the game

I think you get the idea.