This article describes the design, implementation, and evaluation of MiMaze, a distributed multiplayer game on the Internet, and, more precisely, it describes the design of dedicated transmission control mechanisms. MiMaze is implemented on a completely distributed communication architecture based on the IP multicast protocol suite (RTP/UDP/IP). This is the first work to analyze a distributed interactive game on the multicast Internet. The major element of the MiMaze architecture is a distributed synchronization mechanism that guarantees the consistency of the game regardless of network delay. This article provides on evaluation of the MiMaze game on the MBone, and discusses approaches to monitor and evaluate this new type of application. The main contribution of this work is to show, based on on example, the feasibility of this new family of applications on a best-effort network. It is shown that real-time interactivity can be maintained, provided that some level of inconsistency can be tolerated by the application. This work also highlights the role of multicast as an enabling technology for a real-time Internet.