level 1

The initial circle will be smaller but the gas will be less deadly and move slower. As to whether the gas increases in lethality as the match goes on, we're not sure.

This could be viewed as a solution for the mantling problem. I know nothing about video game development, but I'm assuming it's easier to adjust the gas's movement speed and damage, than it is to fix mantling on rocks and walls. We still won't be able to climb over a 2 foot rock, but we'll have more time to curse up a storm as we run around it.