Half-Life: Opposing Force was released in 1999 by
Gearbox Software as the first official expansion pack for
Valve Software's hit
Half-Life. It adds several new weapons and a few new
monsters to the existing game, as well as a single player game roughly 60% the length of the original.
In the original Half-Life, you play Gordon Freeman, a scientist in the Black Mesa Research Facility attempting to survive after an incident that caused hostile aliens to teleport across a dimensional barrier, yadda yadda yadda. Also involved are government controlled marines who have orders to kill everyone, even you.
In Opposing Force, you play as a marine named Corporal Adrian Shepard. The game starts with you getting shot down over the facility and getting cut off from the rest of your squad. Wild hijinks ensue, aliens are killed, and a shady group of government controlled special ops commandos start shooting at you.
Often abbreviated as "Op4", this game also adds some new multiplayer options to Half-Life. All the new weapons are available, of course, as is a new capture the flag mode pitting the BMRF crew against the marines.
If you don't have this game and do decide to get it, do yourself a favor and get Half-Life: Blue Shift, which comes with this as a sort of bonus. I think it's about the same price, it doesn't require the original Half-Life, and it also has the high-definition pack, which really improves the quality of many of the models in the game.
wonko: If this is the best story of any game you've played, then you obviously haven't played many games. Like, er, any RPG ever made.
ukyoCE: The wrench doesn't really charge as such. You just hold secondary fire down for a bit, and it does more damage as compared to the primary fire, which just swings it. Also, the AI is pretty smart, just not when it comes to dealing with the terrain. When it comes to shooting, grenading, or pummeling you, it knows its stuff. But yes, your allies are dumb as bricks.