Installed, spent 10 mins running about in a stratjacket with no hints about what to do, while getting killed over and over again. Uninstalled, threw it away (literally, it's in the bin outside).
If game devs can't be bothered to include any instructions, then I can't be bothered to buy their games.
Just plain bad - 1/10. A much better alternative is L4D2 - looks better for sure, and actually has some sort of plot, unlike this mess.