People like your idea, but I don't understand it. What are they jumping to, exactly?
Ok so two people are on a plateform
On a wall somewhere a timer comes up counting down from ten seconds
After five seconds the timer will dissapear
The two users will have to time when the remaining five seconds are up, and when it goes to zero, the plateform dissapears, and the one who jumps with the best timing will live a bit longer than the one who misses the mark, and they will be crowned the winner.