It appears that the most relevant review structured data type is the critic review. This is because it isn't a combined score from reviews submitted by many users which would use the user review schema. It also meets Google's criteria for a critic review:
- Authoritative human editor(s) must create, curate, or compile content for critic reviews.
- Only include critic reviews that have been directly produced by your site, not reviews from third-party sites or syndicated reviews.
- Don't add critic review structured data for adult-related products or services.
However, Google probably won't use the structured data from your games review website. Google says that it will only show critic review rich snippets for:
- Local businesses
- Movies
- Books
Until Google shows star ratings for game critic reviews, there is no benefit from implementing the structured data on your site. If you were to implement it, you would have to hope that Google starts to show star ratings for game critic reviews in the future.