Is this film in the future or another dimension entirely?

I love this film, and find it very sophisticated. Though, the songs themselves lead the film in a entirely different direction when in the "assimilate" song shows a Encyclopedia Britanica", and in "To be King" the villainous chancellor mentions about how previous brigands and humans of the past would do things, which makes my references to this film being like "planet of the Apes" a little too close for home.

What do you think?