The hoverboard reacts differently based on the surface. Developers calculated the friction coefficients of snow, water and pavement, so even though the board isn't on the ground, you have to alter your movements depending on the terrain.
PC: Half-Life 2
The first-person shooter with the most interactive environment. Coming this winter; Price not set; half-life2.com
Other games' computer-controlled characters have just one means to accomplish their goal. The bad guys here can interact with their surroundings just like you, and they're just as resourceful.
By linking a vast catalog of physical properties of real-world materials to the textures used to simulate them in the game, brick, wood and steel objects, for example, all deflect bullets differently.
Valve took particular care with its "ragdoll" physics, so a body not only careens off a wall like a bag of bones and flesh (as opposed to, say, a steel drum), but its motion changes as it gets mangled. Cool.