On the other hand, it's possible to go too overboard and have a billion sliders, like TES IV: Oblivion.
Videogames, by definition, ONLY have pregenerated content. Either stuff which the developers put in specifically, or put in systems which allow certain semi-emergent behaviors.
That depends on how you define "pregenerated" and how you define "content".
The operations/actions/activities/structure of the game are generally fixed. It IS possible to dynamically generate code ( although that is usually frowned upon ), and it is possible to design a game with loadable modules ( although this is rare for performance reasons ).
However, the data on which the game acts is often not known at compile time, or can be augmented at run-time, and increasingly is generated at run-time from pseudo-random, or completely random seeds.
What is true is that all today's standard computer designs will only ever do with data what they are programmed to do ( however tortuous that programming is ), such that "Artificial Intelligence" contains no capability for understanding context and developing reasoning.