Around 4-5 years ago I stumbled upon this video. It's a real time map of the Black Mesa incident that tracks Gordon, Barney, and Adrian's journey through the facility on a single timeline. While it's a fairly simple idea the execution is superb! Every automated announcement, piece of radio chatter, the video feeds fading in and out, and the personnel count slowly ticking up builds tension so well (there's some fantastic use of audio assets pulled from the Black-Mesa remake). Additionally it makes the last moments of the Opposing Force expansion all the more harrowing, since you can see just how alone Adrian really is.
Trust me, its well worth a watch.
