However, after several months of delays, Sierra terminated development on the Dreamcast version of "Blue Shift" on June 16, 2001, and the company instead released "Blue Shift" for the PC on June 12, 2001. Afterward, Gearbox began working on a "Half-Life" game for the PlayStation 2. The game, "Decay", was showcased at E3 2001, where Gearbox demonstrated the game's use of new model sets, which were around twice as detailed as those in "Blue Shift". For several years, Valve secretly worked on the sequel to the original "Half-Life", "Half-Life 2". For the game, Valve developed a new game engine, Source, which handles the game's visual, audio, and artificial intelligence elements. The Source engine comes packaged with a heavily modified version of the Havok physics engine that allows for an extra dimension of interactivity in both single-player and online environments. In the trilogy of episodic games that followed "Half-Life 2", Valve made minor tweaks to the game's engine. In "Half-Life 2: Episode One", Valve modified Alyx's AI to allow her to react to the player's actions because of her significant involvement in the game. The game runs on an upgraded version of Valve's proprietary Source engine, and features both the engine's advanced lighting effects, and a new version of its facial animation/expression technology. On February 6, 2013, while speaking at the 2013 DICE conference about storytelling in games and film, J. J. Abrams and Gabe Newell announced that they had plans for a game and a film collaboration. Abrams said, "There's an idea we have for a game that we'd like to work with Valve on," while Newell said, "We're going to figure out if we can make a "Portal" movie or "Half-Life" movie together". In an interview in March 2016, Abrams stated that while he has been working on many other projects since, he still has plans to direct these films in the future, with both films in the writing stage. A short film, "Half-Life: Uplink", was developed by Cruise Control, a British marketing agency, and released on March 15, 1999. However, Sierra withdrew it from circulation after Sierra and Valve had failed to resolve licensing issues with Cruise Control over the film. The critical reception of the film was very poor. The film's plot was that of a journalist attempting to infiltrate the Black Mesa Research Facility and discover what was happening there.