A demonstration and discussion of the effectiveness of an animated and interactive simulation of cardiac and/or respiratory arrest with tools to allow the user to reverse the fatal course of events. The simulation is designed to reinforce and teach the American Heart Association's course in Advanced Cardiac Life Support (ACLS). Using an animated interactive simulation allows the student to rehearse various critical events without assembling all the components typically used in the ACLS course "MegaCode." The simulation is written in a commercial authoring shell made by Authorware, Inc, and currently runs on an Apple Macintosh II platform. Cosmic Osmo (Activision) is an animated and interactive exploration game based in Hypercard that allows the user to explore and control the game by clicking on various switchs, buttons, objects, even telephones. The interactive spirit of this program has been carried over to the ACLS tutorial.