1. A system for changing the state of a user interface (UI) element visually marked on physical objects, comprising: a plurality of physical objects, each comprising a unique identification code (UID) and each visually marked with a UI element of a computer program; an interactive surface that has no display screen, and is configured to detect the UID of an object, to derive the location and orientation of the object, and to measure capacitance change caused by the object and subsequently by a touch action upon the object, upon the object being placed on the interactive surface; a sensory accessory that is operatively controlled by the interactive surface, and indicates the current state of the UI element by exhibiting a sensory pattern; wherein, during runtime execution of the computer program, and in response to a touch action upon a first object, the interactive surface is configured to detect the touch action and direct the sensory accessory to indicate a new state of the UI element of a second object that is different from the first object by exhibiting a new sensory pattern for the second object.