Half-Life Generation Big Box PC CD-ROM Half-Life and Opposing Force

Half-Life: Game of the Year Edition (PC, 1999)

Half-Life Opposing Force Big Box PC Game Expansion Valve CD-ROM Classic Sierra

Half-Life Opposing Force Big Box PC CD-ROM Game Expansion Pack Valve FPS Retro

HALF-LIFE Generation PC CD Game - GOTY Edition & Opposing Force Counter Strike

Half-Life Opposing Force Big Box PC Game Expansion Valve CD-ROM Classic Sierra

Half-Life Blue Shift Big Box Version for PC CD-ROM Sierra

Half Life Big Box PC CD-ROM Game Valve Sierra Vintage Retro FPS UK PAL Version