Debriefing and simulation are two complementary and indivisible phases for the use of serious game. However, practices of debriefing vary depending on the objectives and the context. With the advent of new virtual reality simulations, it is interesting to identify methods of debriefing for the trainer and learner in this situation. This paper provides a global review of debriefing in a serious game context and considers the findings tied to a virtual reality context. The purpose of this analysis is to find a proper solution and to use virtual reality technology to improve the debriefing experience. We finally propose a tool for virtual reality simulations that provides an immersive debriefing system that includes a replay system of the simulation occurred as well as a possibility to restart at any moment of the replay. As such, we think that the participant can have a better understanding and reflection of what he/she has experienced as well as a possibility to explore other choices.