Platinum Arts Sandbox Free 3D Game Maker is an open source game design program for kids and adults based on the Cube 2 Engine. Through the ingame and cooperative editing and focus on ease of use the program is easy enough for kids to use but powerful enough for full game projects. Sandbox includes Save The Princess Gameplay, an RPG Maker, a Sidescoller maker, a Movie Maker aka Machinima, Save The Banana Base Capture, and more! Sandbox is already being used in many schools and colleges throughout the world and included in game design contests.
The 1st tutorial of Platinum Arts Sandbox Free 3D Game Maker. More information at SandboxGameMaker.com