The difference is slim, but what's great is that the NPC character faces are similar, and the level of detail on the aliens and creatures is exceptional. These ugly little critters are just as disgusting as they were on the PC, and in fact, one could honestly say they look better. As for all of the functionality in the PS2 version, players have access to sweet HUD, which along with showing ammo count, weapon category, health, HEV suit level, flashlight, displays a reticule that indicates whether the living organism inside it is friendly or non-friendly. Selectable characters feature Gordon Freeman, Dr. Colette Green, Dr. Gina Cross, a military soldier, a scientist, and a security guard. There are 10 maps to choose from, including Basement, Debris, Water Canal, Skirmish, Waypoint, Signal, Office, Snark Pit, Datacore, and Stalkyard.
Players can choose the frag limit and the time limit.
Controller setups can be decided with the mid-game menus per player. The two-player mode moves quite fast, and the framerate keeps up better than average. It's about 50-60 fps, with smallish levels that have second and third story boxes, crates, and ladders that provide ample use of the vertical assault. Half-Life itself is a fascinating game. In essense, you face off with a plethora of brilliantly designed alien creatures that are all part of a much bigger story.