So is everything that happens to her in the movie all in her imagination because she is on drugs or just mental?
I tend to view movies within a very framed context. I don't put much weight into judging it strongly by it's character development, plot cohesiveness, acting or any of the usual crap.
This movie I see as a purposeful nerdfest mishmash with a plot designed to fold around a mix of music videos, random fantasy elements, and video game elements.
The creators probably figured that it was impossible to make a cohesive world with all of that.. They could have gone with some crazy person's delusions, drug trips, or a person in VR..
Instead they went with something a little unexpected.. An apparently sane person with a ridiculous imagination (on drugs maybe), that escapes into fantasy world not to escape reality but to somehow make events happen in the real world.