Dark Interval is a total conversion mod, the new incarnation of the Original Storyline of Half-Life 2. You can find your way through the nightmarish world of devastated Earth. Starting from the suburbs of City 17, then continuing through the alien factories, the underwater base and the Citadel, you can feel that dark atmosphere of the Original Storyline. Development started on Apr 10, 2010.
A player starts in the valley after infiltrating a waste disposal facility. The valley primarily serves as a place for dumping all the acidic and radioactive reagents and metal wrecks; the place has a relative minimum of guard activity.
The key part of a gameplay experiment was to implement stealth elements. If player can keep out of well lit areas and minimize noises from footsteps and gunfire, it'll be possible to avoid most confrontation with soldiers. It may later come useful to try not to alert enemy in the facility. As the result of Gordon loosing most of his weapons in the train crash, the enemy brought upon him on a full scale may easily overpower him.