Using virtual environments (VEs) is a safer and cost-effective alternative to executing dangerous tasks, such as training firefighters and industrial operators. Immersive virtual reality (VR) combined with game aspects have the potential to improve the user experience in the VE by increasing realism, engagement, and motivation. This article investigates the impact of VR technology on 46 immersive gamified simulations with serious purposes and classifies it towards a taxonomy. Our findings suggest that immersive VR improves simulation outcomes, such as increasing learning gain and knowledge retention and improving clinical outcomes for rehabilitation. However, it also has limitations such as motion sickness and restricted access to VR hardware. Our contributions are to provide a better understanding of the benefits and limitations of using VR in immersive simulations with serious purposes, to propose a taxonomy that classifies them, and to discuss whether methods and participants profiles influence results.