Abstract: Device, system, and method of interactive game. For example, a system includes: a server to host a virtual hub associated with a plurality of spokes, wherein each spoke leads users to a plurality of virtual worlds having a common characteristic, wherein the virtual hub and the spokes comprise a virtual worlds network, wherein the server comprises a single sign-on module able to receive from a user a first set of sign-on data items, and able to sign-on the user to a first virtual world and to a second virtual world.