I don't see a status released tag or filter but I'm on mobile so maybe it's a desktop view only type of deal, but there's definitely nothing in tags and none under filter that can sort or find things based upon a released/finished status.
Viewing post in Tag merges and suggestions
Hm… In the browser version of the search, it filters just fine. (Example Search: Top free Visual Novel released Games for Linux tagged LGBTQIA )