Another big difference is whether the dungeons FELT linear or open ended. MOST Final Fantasy dungeons, and RPG dungeons as a whole, are fairly linear, and that's okay. Part of making a good game is to be able to steer the player in some manner of direction, while at the same time making it FEEL open ended and enjoyable. Being able to steer them means being able to plan out cohesive story arcs and important events along the way at good intervals. But players shouldn't KNOW that they're being lead around, because then they feel stifled. FF6-9 did a great job of this. You got lots of dungeons with winding paths and small branches in order to make it feel like it wasn't a boardwalk layed out for the hero (which totally breaks the fourth wall), but in reality, the progression through the dungeon had to be done in a specific order, and there were some clear points of arrival and departure that gave the player distinct short-term goals. That's good design, IMO. With 10, you start to see long stretches of straight paths from A to B with only slight jogs along the way. FF12 did it's best to rectify this, but went to the opposite extreme by making huge empy spaces that were devoid of interesting obsticals and clear dilleniations. So FF13 went back to the FF10 method, but squeezed it even further. What they really should be looking back to are Lunatic Pandora, Ispen's Castle, Temple of the Ancients, and the Caves of Narshe. Since FF9, Square's graphical prowess has improved, their dialog may have improved, but their sense of good dungeon design has fallen greatly, they need to look back to their pre-rendered days for inspiration. And I don't think it has anything to do with the 2D > 3D switch, because there are plenty of 3D games that have had GREAT dungeon design in 3D: Ocarina of Time, Skies of Arcadia, Dragon Quest VIII, the list goes on.