I tried searching them again and this time I DID find them. I think I just typed in Chronicles of Mystery before, rather than the whole name. Also, clicking on "Adventure" games helped immensely.
Don't bother using Big Fish's search. It's utter garbage.
Use Google (or DuckDuckGo or Bing or whatever search engine you like best) and search for:
"Chronicles of Mystery" site:bigfishgames.com
The two "Chronicles of Mystery" games that are adventure games are "The Scorpio Ritual"
and "Tree of Life." The others are casual games.