The rank percentile is a great suggestion and after that take the average rank I guess?
Ratings per year is a possibility.
Complexity: Indeed I wanted to remove some of the more complex games because I don't have time for them. Although on reddit there was a nice discussion that the weight is composed of complexity & depth
An second thought the rank percentile would be heavily influenced by the amount of ratings given per user.
If you rate only 3 games you think are great with high ratings, then one of them is going to recieve an awful percentile.
The same 3 great games rated by someone with 5000 ratings will have much 'better' percentiles, just because all the crap games.
Ratings per year is a possibility.
Complexity: Indeed I wanted to remove some of the more complex games because I don't have time for them. Although on reddit there was a nice discussion that the weight is composed of complexity & depth