The Combat Medic, who can help heal you as well as NPC’s. The Soldier, basically the character that can help with firepower. There will be three types of Marines to help you through the game. Opposing Force offers an extended multiplayer mode like capture the flag that has new levels, items, and power-ups. Go through the game’s levels and kill your enemies and solve puzzles to move further into the game. This first-person shooter does play like Half-Life. As you push through with your task, you are separated with your team and is forced to seek help with the personnel of Black Mesa and escape the dangers of the base. By order of the government, Corporal Shephard must crush the alien threat and take out all witnesses. Marine Corporal sent to the Black Mesa Research Facility in New Mexico. This is an expansion pack for the game Half-Life. Developed by Gearbox Software and published by Valve. Half-Life Opposing Force is an action video game.