Worked perfectly on my mic!
I agree with igott about the multiple breaths, though; if you wanted to add that but still keep it challenging, you could add obstacles that you can't run into (and hopefully no one would run out of breath!) You also have the built in challenge that, even though they're allowed multiple breaths, they can't breathe too hard and they can't let the plane hit the ground. So I think it could still be challenging and not go on forever.
The only question is, would it become a health hazard?
Hmmmm...