Mutation Switch mode( not a good idea but meh )

So it's a big map and every one are humans and they run around happily until one random guy get's infected(he got more HP then a titan mutant) and he has to infect someone else to give him the infection( the guy who gets infected is frozen for 5 seconds so they can't spam on each other )and you get 1 point if you stay clean for 10 seconds and it goes on like this for X time.
It's a bad idea but i just wanted to share it.