Motion-design – is what stands for “feel” in “look and feel” interface principle. The reactions of interfaces and game elements to player’s gestures, the transitions from interface states – the things a flash game developer can’t omit. What is the role of these interactions and what are the variants? What attention is needed to their deliberation and programming? We are going to discuss what is easy and difficult to realize, why this should be done and what is the final objective: from the known examples to the description of the concrete realization methods.