## 4 Results
### Player Experience  
This section identifies aspects regarding the players' experience in VR gaming environments in terms of immersion and describes emotional responses evoked when the player interacts with the VR game system (Table 8).  
User experience is crucial in VR games since they can directly influence the levels of immersion and enjoyment. User interaction in the VR gaming environment raises significant design challenges (e.g., S10) and demand specific solutions. Similarly, VR games need to be usable and respect usability guidelines. For instance, several locomotion techniques on player perception and system usability within the environment should be further investigated (S08).  
Players also seem to like the fact that VR games allow them to experience worlds that are impossible to experience in the physical reality. They enjoy such experiences because certain locations are impossible to reach, because the events took place in the past, or even because the story is based on a fictional setting. (e.g., S01, S02). The increased interest in such games is recorded in different works that even report long queues of people waiting to experience the virtual world (S28).  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Effects** & **References** \\ \hline Immersion & S01, S02, S03, S04, S05, S06, S07, S08, S09, S10, S11, \\  & S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, \\  & S23, S24, S25, S26, S27, S28, S29, S230, S31, S32, S33, \\  & S34, S35, S36, S37, S38, S39, S40, S41, S42 \\ \hline Usability & S01, S02, S03, S06, S07, S08, S09, S10, S12, S17, S19, \\  & S22, S23, S26, S27, S38, S41 \\ \hline Aesthetics & S01, S02, S04, S05, S08, S09, S11, S12, S21, S22, S26, \\ \hline Physically impossible experience & S01, S02, S06, S13, S15, S17, S18, S20, S22, S23, S26, \\  & S27, S28, S30, S32, S34, S35, S42 \\ \hline Feedback & S03, S06, S22 \\ \hline Training needed & S08, S12 \\ \hline Motion sickness & S08, S09 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Player experience (selected studies).  
VR games also apply aesthetic principles, not only to make the gaming environment attractive but also to recreate the historical details of monuments and objects, like in the case of the Plavana Project that allowed people to explore the Konark Temple Grounds (S21).  
Many works focus on the evaluation of the gaming experiences. In particular, researchers are interested in the effects of such games on the cultural experience. From self-reports to physiological data coming from EEGs (i.e., S03), the user experience is analyzed as well as the learning gains. People seem able to connect the virtual content with the physical one and thus, their virtual experience seems to significantly enhance the physical one (S06).  
S09 highlights the importance of the training of player-users, as there are many people who are not familiar with VR equipment. Most players are used to standard controllers for gaming consoles and computers and using a new kind of controller (e.g., VIVE controllers) might be obtrusive for many audiences.  
Moreover, VR-enhanced museums should be able to serve multiple participants simultaneously (S09) and this might pose administrative challenges.  
Finally, certain studies also report further problems with VR games in cultural heritage, such as motion sickness (S07, S09)