Crazy Machines

In the game, players build imaginative machines that turn cranks, rotate gears, pull levers, and more to build a unique contraption. The player can solve more than 200 challenging puzzles and experiment with gears, robots, explosives, and more in a virtual lab. The game uses a physics engine to simulate various in-game variables such as air pressure, electricity, gravity, and particle effects. Source: Wikipedia, "Crazy Machines", available under the CC-BY-SA License.