You're quite close, actually.
The Shadowlord's castle is the end of the game. The key quest is the end of your free roaming. The junkyard is the only sizable bit (and you're on the last chunk. First visit: get upgrade materials, second visit: find mother, third visit: get MA Fourth visit: kill PN-03 (ha ha, pinocchio) ). The forest of myth is even more straightforward than the first, since it also uses the visual novel format. Facade is all cutscenes and plot before a boss fight (no dungeon!) and the Aerie revisit is no big deal.
The final dungeon itself takes a bit to get through, but it's so damn fun the time seems to fly by. Love that level.