Due to the nature of some Interactives, I think story-driven "Kraxis-classical" ones should have at least 2, or 3 months limit before being put into inactive mode and dropped from the list -- King Henry's magnificent English one takes a long time between each chapter, for example. They are subject entirely to the author's whim and write-ups between each chapter will take time.

Multiplayer ones, due to their nature, should be around 1 month or even 2 weeks limit before being dropped into inactive, except may be the full blown interactives like 17th Century where outsiders don't know about the behind-the-scene games being played between players and could've taken longer.