Not sure if I'm misunderstanding you, but to sort by last update that doesn't go by thread, go to the forum page and click on games. From there you'll see sort and filter options on the right side. Hope that helps!
I will say that a suggestion I have would be that the page I'm referring to above automatically sort by last game update instead of last user message, but that probably goes against the whole 'being social' drive this site has been going for lately