The world of Ivalice is actually playable in four games: Final Fantasy Tactics, Vagrant Story, Final Fantasy Tactics Advanced and Final Fantasy XII. The big question is how these four games and their respective worlds tie into each other, which the retrospective covers in the last section of this episode. There are more games planned to occur in the world of Ivalice as well. In the next episode of the retrospective they'll cover all the random Final Fantasy stuff like the spin-offs and movies.
See also: Part I & II, Part III, Part IV, Part V, Part VI, Part VII, Part VIII