I don't know the answer to this, but how hard would it be to have a program that looks through all the stories at the end of each day, and works out which are the top 5 in each category, according to their current rating, and lists them on the front page as the top games for that category. Stories on the list might change, as people continue to cast votes, but it would be an accurate representation of which games are (at that time) the high voted games.
I don't think going by simply how many times it has been played is all that relevant. After all, the same person can play a game over again, a dozen times, if they wanted, making that number go up. Even the author, looking at their own game, to check bugs people report, would make the number go up - so it is no solid representation of how many different people have played the game. Not to mention, the Times Completed number is often quite different. In fact, the Times Completed is a good number to go by, since it means someone not only played the game, but liked it enough to actually reach an ending.
However, Times Completed changes everytime a story gets unpublished, then republished. You'll note Ulysses currently has Times Completed: 10, User Ratings: 12. However, more people have completed the game than have voted for it. The number was reset to zero when I updated the story, and now is lower than the ratings instead of higher. So, that is not really a good number to go by either.
I know, not good publicity for myself using my own story as an example there, however it shows that the numbers change, and don't always match up. So, actual user ratings, and voted score are the most important things to measure by, in my opinion.
Rather than award people a 'featured game' perhaps each story should have a "Days Featured" score, which goes up by one at the end of any day that their story is put on the front page, due to having a high user rating score on that day. Then, perhaps the Top Game category would show the current "top five" stories according to their "Days Featured" score. In other words, the high rated stories that have been featured for the longest amount of time, would be the Top Games of the site.
Does this system make sense to people? Any suggestions?