Typical disaster is a small single player episode for Half-Life. It tells a story about Gordon Freeman's job in one of those dangerous top-secret research facilities.
Though it had some interesting level design... some things could be improved upon. For one, some of the Xen levels were especially hard to navigate. When you had to use long jumping... it was almost impossible unless done exaaaaaaaactly right. Also there were some small AI bugs.
Some touch-up of level design and this short mod should be wonderful fun.