Half-Life 2

Game information:

In Half-Life 2 the player takes on the role of Gordon Freeman, as in the original Half-Life. Armed with numerous weapons, he has to make his way through a series of levels, encountering both "trans-human" troops, also known as the Combine, and hostile alien creatures. As in Half-Life, the gameplay is broken up by a series of puzzles; however Half-Life 2 also includes physics-based puzzles. For example, one puzzle requires the player to either turn a seesaw-like lever into a ramp by placing cinder blocks at one end, or to stack the cinder blocks into a crude stairway.