1. A system comprising: a network-connected computerized appliance coupled to a data repository; and software executing on the computerized appliance from a non-transitory medium, the software providing a building game comprising: a set of selectable atomic three-dimensional objects, each having a specific size and shape and one or more join features enabling joining to other atomic objects having a compatible join feature; a function enabling a user to select a surface on a selected atomic three-dimensional object, and to rotate the surface about either or both of two axis using handles provided on or near the surface, rotation of the surface changing shape and dimensions of the atomic three-dimensional object; a function enabling a user to resize a selected atomic three-dimensional object either larger or smaller using handles provided on or near the atomic three-dimensional object; a function enabling a user to translate, rotate and join selected atomic three-dimensional objects to construct more complex objects that combine one or more atomic objects, wherein in rotation specific rotation increments are enforced to ensure that the compatible join features properly align for join; and a physics simulation engine tracking and changing physical properties of both the atomic objects as the atomic objects are selected, changed in shape and size, effecting their physical properties, and complex objects assembled from atomic objects, and providing physics simulation of all objects during play of the game.