The Source engine is behind a celebrated run of action and shooter games, with over 350 tracked on GameScrobbler. It's the foundation for landmark titles including Counter-Strike: Global Offensive, the puzzle-driven Portal, and the co-op survival of Left 4 Dead, plus Counter-Strike: Source and Half-Life: Source. The catalogue captures Source's reputation for responsive movement, physics, and multiplayer-focused design across some of the most recognizable names in the medium.