You can finally rescue Half-Life's guards and scientists thanks to this mod inspired by Lemmings
(www.pcgamer.com)
Half-Life: Lemmings lets you save the trapped employees of the Black Mesa: Facility.
Trailer:
I actually tried to do this in the OG GoldSource, but I could never get them to move to the next map. This was on the early maps (office complex), I was too busy trying to stay alive in the later maps.