
A lock-on mechanic, similar to auto-aim from the original game, was introduced. The view roll from the original game when strafing left or right returned. Several key changes from the unreleased Dreamcast port made their way into the PlayStation 2 version, including the movement indicator on the HUD and simplified long jumping, allowing the move to be performed simply by pressing the jump button while in mid-air. They must work together with the assistance of the science team to seal the rift between Earth and the borderworld Xen. Half-Life: Decay is an exclusive multiplayer cooperative mode for the PlayStation 2 port of the game where the players take on the roles of Dr.

When entered, it causes the game to prompt for an expansion disc. This can be played using an undocumented cheat code discovered by the project leader of Half-Life: Decay 's PC port. The only released addon was a port of Half-Life: Uplink released on a PlayStation Underground demo disc in the June 2002 issue of the Official PlayStation Magazine. Marc Nagel from Sierra confirmed the game would receive mod support. On-line multiplayer did not make the final cut as the console's connectivity options were not available at the time for the developers to implement.

It was later changed to two-player mode with eight bots. The game was announced by Sierra on Novem along with a two-player cooperative campaign known as Half-Life: Decay and a four-player multiplayer mode featuring 12 exclusive levels. They received their development kits in early April.


Gearbox started making plans for the port with Sony in February of 2000. The companies began exploring the possibility of bringing the game to the PlayStation 2 as early as November of 1999. The game also features a two player multiplayer deathmatch mode (via split-screen) titled Head-to-Head and a new cooperative expansion called Half-Life: Decay that allowed players to play as the two female scientists Dr. The levels were also updated and extended based on the work from the Dreamcast port, and most of the bugs were ironed out, making it the most technologically advanced and stable version of the game to date. The character models are much more detailed, featuring eyes that track movement, facial expressions, and jointed fingers. The most noticeable difference in this port is its improved graphics.
