In order to make games rather than worlds, "3D Construction Kit" also allows for the addition of conditions, using the very simple-to-program Freescape Command Language (FCL). Sensors, animations and interactivity with the elements can be added with relative ease. Players are able to move around the virtual worlds by walking or flying. Elements such as proximity sensors triggering events, enemies making the player appear in another zone of the game when hit, and the ability to activate switches in order to open doors, make the worlds created with "3D Construction Kit" come to life and add a level of uncertainty to the gameplay.