[@Fabricant451]

The difference between X's linearity and that of XIII is:

1) X still has towns, NPCs, and various areas that let you slow down, relax, take in the sights, and learn more about the culture, world, and backstory in an organic way. XIII has you on the run for most of the game and does the bulk of its worldbuilding through datalog entries.

2) Many areas in X have multiple or branching paths, whether or not they all lead to the same exit (ex: Kilika Island), as well as more open areas (ex: Thunder Plains) so even if you only have one direction to ultimately go, it's not just one constant tunnel. Most of XIII suffers from hallway syndrome, and almost all deviations from the narrow main path are dead ends.

3) X gives you control over your whole party within the first few hours of the game, as well as a fairly open-ended leveling system that becomes totally open by the end of the game. Every play through can be different if you want. XIII locks you into who you play as, what they can do, and how much you can level up till like 30 hours into the game. Every play through is essentially the exact same.

4) X spreads its optional content across the game. Finding Al Bhed primers, playing Blitzball, fighting Belgemine, nabbing extra aeons, finding spheres left by Braska's party, unlocking legendary weapons, etc. XIII throws all its optional content into one area near the end of the game.

I hear this "X is linear so why do people complain about XIII" argument all the time, but it frankly feels rather disingenuous to me if you've played both games.