The pack included Team Fortress 1.5 with it as well. Well, Half-Life, which is the game of the year, has some several expansion packs, as you know. The storyline is just totally screwed up. You play as a soldier called Adrian Shepard, and the intro goes you are in a plane with some military guys with you. As you watch them talk, your plane crashes and, you crash near the Black Mesa lab, and the place is overrun by aliens.
Soldiers die and that.
You wake up in a room with a scientist which saves you nearly from death and you wait for that. Well, this game is almost as good as Half-Life. Nearly the same as Half-Life. This time, you still get to shoot aliens, and repeat yourself in Half-Life. You get new weapons like some weird tool, a hand-knife, and some weird alien claw, also with another machine gun, a sniper rifle, and cool sick weapons to add to Opposing Force.