Try following this link for year filtering? Top free Adventure games from 2015 - itch.io if you end your itch io URL with year-#### where # is replaced with the year I think that gets you what you want.
That's weird, I notice the feature is either removed or highly erratic. I don't know how I did it, but I managed to get an instance of year filtering as shown in the big image.
but recently I only see a shorter list which is weird.
