I find another fact interesting from a business point of view: Crytek made their quite open shooter more narrow, like a rail shooter with more scripts to be more successful and to bring it closer to CoD and similar successful shooters.

At the same time shooters from Bethesda (Rage and Prey 2) do it exactly the other way around. Both used to be narrow rail shooters and become more open in terms of level design and freedom of choice. So who is right in the end? Wouldn't it be easier for the gamers when Crysis2 kept open or wided even more while Prey2 kept a corridor shooter using portals and gravity?

Sometimes the number of a game does not tell much about the relation between predecessor and the new part.