While the whole number ranking concept seems novel, I don’t think it really helps the player in deciding if they should play a game. If I told you that some game had a score of 39, could you make a judgment off of that alone? The content descriptors are a good idea though.
Yeah the number alone is too vague to be useful by itself. Although it could be a good way to quick-search through stuff. ex - a search function that allows you to specify a rating range (adventure games with content rating 50 or lower) and then you could go through them in more detail to view the individual content warnings.