Surviving the Holidays is a single-map campaign that I made for Valve's Left 4 Dead 2. It is playable in campaign, versus, survival, and scavenge modes. It took me an entire
year to make, but some lag-issues aside, I'm quite proud of how it turned out, and I think it is one of the prettiest-looking implementation of Source Engine that I've seen. Does it
have lag problems in places? Yes. Some of them are because Source Engine was never designed to support wide-open, high-detail environments, which I only learned once I was several months
deep into the design. Some of those lag problems are due to poor optimization on my part. I'm working on these alone, and I'm not a professional modeler, which makes optimization tough
in Source Engine.
On rare occasions there is also a problem that causes severe, slide-show-esque lag, but it appears to be related to Source's audio system, and short of stripping all of the music out of
the level, I may not be able to fix it. If you do know how to fix it, please leave me a comment, because I really would like to know how.