I know it's a beta, so most likely my suggestions are in your plan already, but:

1. If you are planning to go global with thousands of games, you need to have more filtering options (categories, year of production, etc.)
2. People are lazy, so they don't want to google titles to see a game description. It should be on your site.
3. There should be a rating for a game too, not only for a seller. Same goes for comments.