Pros
+ Haven't seen many people who have done this rare. (Black mesa stories)
+ Story over all looks good.
Cons
- Mostly screenshots. Doesn't keep the viewer entertained.
- Not a lot of the actual story.
Conclusion- I think it was quite good over all. You have the basics it's just for preparation could be done a bit more. I'd suggest running videos instead of screenshots, and maybe instead of writing you voice over laying the video. This would keep viewers entertained. If you could add more dialogue, and also...keep in mind that the "Black Mesa Source" should be out soon. So you could always prepare for the time being until it's released. Black Mesa source will be well known on release as well with videos.