PC Gamer wrote:

One of the things I like most about Killing Floor 2 is the way it mixes absurdity with graphic violence. This week's Weekly Outbreak—essentially a temporary mutator—goes all-in on gore and humor.

Earlier in the summer KF2 added a shrinking zeds, and now we continue to see Tripwire play with physics in "Up, Up and Decay," where shooting and slashing zeds will cause them to fill with air.

"As Zeds receive damage they inflate," Tripwire tells me via email. "After some time they start to deflate. Once they reach max inflate they turn into death balloons and rain down gibs. The idea is if you don't finish them off they go back to normal size and heal!"

Complete this challenge, and you'll earn the Hans Plushy Backpack item shown in the trailer above.