In this paper, we investigate technical issues for graphic enhancement and game features of HMD VR games, which are hot issue recently, and try to catch up on research issues to be solved in the future. The successful expansion and dissemination of content has been accompanied by technological advances in the development platform. Virtual Reality is becoming the next generation platform connecting PC, Internet and smart phone. In particular, HMD VR games are attracting popularity and interest from game users because they provide simplicity and immersion that current PC games can not support. However, there are some issues that need to be addressed in order to meet the expectation of users who are familiar with high-level PC-based visual requirements. In this paper, we investigate the performance factors for visual loyalty and explore technological advances of HMD VR to meet high resolution graphics so far. We will also look into trends in the recently popular HMD VR game in 2016 and 2017 and pick up issues that should be considered in future game development.