LandBox

LandBox is a free, exciting first-person sandbox where you can create your own world that you can share with other players. There are ten types of landscape block sizes to choose from: 50x50, 100x100, 150x150, 200x200, 250x250, 300x300, 350x350, 400x400, 450x450 and 500x500. You can add object physics, weapons, enemies to the created world, and also turn it all into a small game. In addition, there are several different biomes, including forests, deserts, savannas and more. You can play either alone or online.