The world of TUG is built up of blocks in a randomly generated world. These blocks can be detached from the ground allowing players the ability to manipulate the world around them. Players commonly use this feature for the building and destroying of structures, and the terraform of local environments. The buildings that players make can range from simple huts designed to protect their seed from the elements and/or aggressive creatures, to expansive metropolitan cities which stretch further than the player can see and where the natural world has all but disappeared.
In Creative mode, you can control the shapes of the blocks you place. In Survival mode, the shape of a block depends on the material. There are currently three possible shapes: sharp-edged cubes, blocks with rounded edges, or blobs/low mounds.