From the original list on Backloggd:
"To be eligible for this list, a game must:
-Have 1,000+ plays.
-Not be DLC, an expansion, a collection, or a chapter.
-Be the most played version of the game it's representing. In the case where an alternate version* of a game has more plays than the original version, the original version is listed as a note.
*I use Glitchwave to determine what should be considered an alternate version of a preexisting game, since to my knowledge it has the most comprehensive version combining out of any game database."