Fantastic Contraption is a physics puzzle game in which the objective in each level is to move all red objects into a rectangular goal area. To do this, you are given a blue rectangular building area and a few different materials in which you can build your device. Standing in your way, however, are a variety of obstacles, ranging from gaping gaps to a sea of circles bent on destroying your red-object-mover-apparatus.
To make your machine, click on the type of material you want, and then click or drag in the light blue "building area" to place it. At your disposal are three different wheels—a clockwise spinner, a counter clockwise spinner, and a regular wheel—as well as two different connectors—a solid "stick" and "water" rod, which can pass through other walls and wheels, but not the environment. Each of these objects has nodes (represented by small, light gray circles) that other objects can attach to so you can create more complicated contraptions.
One nice feature about this game is the keyboard shortcuts. A couple especially useful ones are:
[Shift]+mouse to move items. Note that if you click on a node when using this technique, only that connection will move, whereas if you click on any other part of the structure, the entire device will move. Also, you can use [Shift] click to pan around the level by clicking on the background.
[Command]+mouse (or Ctrl, for Windows users) to delete items.
[Space] to start or stop a test.