Dream and Reality in Popular Culture

A dream is a popular plot device in literature, comics and films, it can serve as a full world for a character to dive into or just a small sign about reality. It has been used by H.P.Lovecraft, L.Tolstoy, L.Carroll, W.McCay, N.Gaiman, C.Nolan etc. All those authors used this plot device differently, creating their variations of dreams and possibilities within dreams. 
As I am mostly interested in defining Reality from a Dream and visual representations of both, I am going to focus on those.

Doctor Who: Amy’s Choice (ep.7 s.5)
written by Simon Nye
Trapped in two worlds, unable to distinguish which is reality and which is a dream, Doctor, Amy and Rory have to find out what is real and wake up before they die. At the end of the episode, both realities are revealed to be a dream.
In both realities, they meet Dream Lord, who from the very beginning is dressed similar to the current Doctor. And is, as appears at the end, creation of a heated up TARDIS.
I really like the idea of the protagonist and the antagonist looking similar to each other, resembling each other in a way. Of course, in the game, it won’t be visible, and it won’t influence the gameplay, but I think it can just be a beautiful detail.

Sandman (Neil Gaiman)
Sandman, Morpheus or Dream has many names and is a personification of dreams in The Sandman comic series.

The Matrix (The Wachowskis, 1999)
Although Matrix is far from the personification of dreams, it is a film that shows the drastic difference between the world of Matrix and Reality. The way physics is broken inside the Matrix world might influence the visuals I create for the game later. There is an effective system of signs, references and allusions, and I can adopt some of them for the needs of my game.
Inception ( C. Nolan, 2010)
Dreams inside dreams inside dreams. A film that is hard to explain, but everyone just knows about it. The most valuable for me in this film is the concept of distinguishing the dream and reality between each other, the totem the dreamers use for this purpose. And the “architecture of dream” term. That is a film that defines the concept of being lost between the dream and reality quite vividly. And I think it might help me to set my own mood for the project.

Chilling Adventures of Sabrina (ep.5 s.1)
Sabrina and her family are challenged by Batibat, a demon, which creates nightmares. This demon tortures Spellmans in their dreams, deriving their worst fears. It is quite a creepy personification of nightmares, but it served as an excellent way to expose the characters through their hidden desires and fears.