## 2 Methods
### Selection of Studies and Eligibility Criteria  
In this review, all authors were involved in the screening process. The titles and abstracts of the studies were independently assessed by each reviewer, and any discrepancies or disagreements were resolved through discussion between the reviewers. Additionally, Zotero 7.0.11 reference management software was used to assist in organizing and managing the literature during the screening process. During the article screening process, studies that involved healthy older adults without major comorbidities were included in this review to avoid bias in perceiving the technology. However, to more fully assess the effects of VR technology, some studies [16] included older adults with mild motor impairments to analyze the potential of VR in improving fine motor skills. Given that these mild impairments do not significantly affect the participant's ability to perform cognitive or physical tasks, they were in line with the inclusion objectives of this study. Two types \begin{table}
\begin{tabular}{c c} \hline
**Database** & **Search Strategy** \\ \hline \multirow{4}{*}{Web of Science} & TOPIC: (aged OR elderly OR frail elderly OR older adult) \\  & AND TOPIC: (virtual reality OR exergame OR video games) \\  & AND TOPIC: (postural balance OR balance OR balance disorders) \\ \hline \multirow{4}{*}{SCOPUS} & [ITTLE-ABS-KEY (“aged” OR “elderly” OR “older adult”) AND \\  & TITLE-ABS-KEY (“virtual reality” OR “video games” OR \\  & “exergames”) AND TITLE-ABS-KEY (“postural balance” OR \\  & “balance” OR “balance disorders”) \\ \hline \end{tabular}
\end{table} 
Table 1: Search strategy for each database. of head-mounted displays are covered in this study: professional-grade head-mounted displays that rely on computer arithmetic and which require a streaming connection to a computer for operation, such as the HTC Vive Pro, and standalone virtual reality (VR) head-mounted displays. The latter can operate independently without the support of external devices, providing a convenient user experience similar to that of a smartphone. Standalone VR devices have a significant advantage in terms of ease of use over professional headsets that require complex configurations, such as the Meta Quest 2. The development of this technology has not only promoted the widespread popularity of VR technology but has also become a technical solution actively promoted by mainstream manufacturers. To ensure the timeliness of the studies, literature screening was limited to studies published within the past five years. This review excluded studies that relied on expensive hardware equipment to minimize the impact of equipment costs on experimental reproducibility. Also excluded were groups involving older people with precarious health conditions, which may prevent patients from being able to complete VR games independently, such as those with Alzheimer's disease or severe movement disorders. In addition, conference papers, unpublished studies (e.g., gray literature or conference abstracts), and non-English-language literature were excluded to ensure the scientific validity and readability of the studies. All of these measures are implemented to prevent bias in the review process. To ensure the comprehensiveness of the literature search, we specified three types of core keywords, which include \"VR games\", \"older adults\", \"cognitive function\", and \"physical health\", and expanded the search with related keywords to cover potential research directions and outcomes. As indicated in Table 1, only one comprehensive search was conducted for this review. The search strategy was applied across the Web of Science and SCOPUS databases using the criteria outlined in Table 1, and no additional searches were performed after this initial search. The results from this search were used to identify studies that met the inclusion criteria for the review. Table 2 outlines the search strategy used in this study.