Level Design Document
In Keeping on Track, players take control of Gordon Freeman as he forces his way through a Combine train depot. The player begins at the bottom of a stairwell that exits out into a train yard. The player must fight through Combine forces that seek to prevent their escape. They will charge in and attack, rappel down from high areas, and push explosive barrels to try to stop the player from escaping. Headcrabs have also nested around the abandoned boxcars, and jump out when the player enters their territory. The player must disable the Combine force field so the train can leave. The level ends when the player jumps onto a moving train and rides it out of the city.
Encounters are scripted so that the player always feels like they are being pursued.
Combine forces are set up to ambush the player and try to cut off the escape.
Reinforcements repel down to the trainyard to continue the pursuit.
At ground level the trains serve as a blockade...
...but they can also be used as platforms to reach new areas.