It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

Sorting by last played does not work on stand-alone games, at least not always, launched a game yesterday, it went to the top, launched another one today, still at the bottom.
For some reasons games aren't getting updated by last played at all now.