Game development can be an interesting thing. 3D Realms' Prey looked completely different in 1995 compared to the final release, same with Duke Nukem Forever, while others like The Last Guardian never shifted focus too much, but there are still somethings that shifted around as development went on. I mean, it skipped a whole console generation.
But what I want to talk about to today are the prototypes of that that somehow made its way into players' hands. Be it official demos, or leaks on the internet, which prototypes of any released game, show a different take on what could have been in the final product if it came out earlier?
Prototypes of unreleased games are welcome too, but I don't know how to squeeze them into the question.