While Room for One is a cool idea in the sense that it turns the typical teamwork you'd see in any given Campaign into an "Every man for himself!" situation, the way this mode functions isn't very well thought out.

-Playing on Advanced or Expert means people are just going to shoot each other to death in order to secure victory.

-Being forced to play on Easy or Normal to ensure people don't teamkill each other is boring.

-Most finales other than Swamp Fever, The Parish, and Cold Stream have rescue vehicles that take a while to show up, meaning everyone is going to be where it appears far before it spawns in, just holding W and praying they get in first, which is boring.

-Being restricted to finales only gets repetitive very fast.

-The mode is essentially just a race to see who can reach the rescue vehicle first, which is fine, but the only two campaigns that truly accommodate this style of play are The Parish and Cold Stream, as well as any other custom campaign that has a functionally identical finale.

All in all, it can be fun to race through the finales of Parish and Cold Stream a couple times, but unless you've got a group of friends that are going to play fair, trying this on higher difficulties is asking for a miserable experience.

By the way the since the person activating the generator at the end of the Sacrifice finale dies, they aren't countered as the "first one out" meaning the entire team is going to be unwilling to leave the bridge as doing so is an instant loss in this mode for whoever does.