The use of immersive virtual reality learning environments (VRLEs) is changing the way students learn and understand things. A VRLE allows its users to get immersed in the simulation, thus giving the sense of being part of the real world that it represents. Virtual Reality (VR) existed in various forms in the past two decades, but its early adoption in education was hampered by its high cost. Emergence of affordable head-mounted displays (HMD) is now making it possible to provide VR experience in classrooms. This paper aims to apply integrative review of relevant studies conducted in evaluating the effectiveness of VRLEs and in doing so reveal the existing research gaps among VRLE studies. This paper identifies salient features of a fully immersive and non-collaborative VRLEs that uses HMD. Salient features were derived from evaluating different instruments used to measure the effectiveness of immersive VRLEs. A framework and example of instruments to evaluate salient features of an effective VR, using Kokoda VR as a case study, are also provided.