Ready Player One could best be described as absolutely maddening to adapt into a movie. First of all, in Ernest Cline’s book you have two separate worlds to deal with: the dystopian slum world America has devolved into, and then the virtual world inside the OASIS that people use to escape their reality. The OASIS is peppered with ’80s and ’90s pop culture references — they become integral to the plot — so it makes sense that Steven Spielberg, one of the people who essentially created the late 20th century pop culture landscape, would be a good choice to direct it.

Collider caught up with Tye Sheridan, who’ll be playing protagonist Wade Watts and his virtual alter ego Parzival in the movie, and he explained how Spielberg would combine the real and virtual stories. Most of the movie, Sheridan said, would be set in the virtual OASIS.

60% of the film takes place in this virtual video game and 40% takes place in the real world.

The idea of the film — it’s established that this video game this virtual reality game is much more glamorous than the real world; people have jobs inside of this game which is called the OASIS, people spend their lives inside this video game. My character is kind of this loser in the real world, but in this video game the creator of the game dies and leaves behind an easter egg hidden inside of the game that holds his trillions of dollars and control of the game and he says whoever finds it in the game is the person who should take over the OASIS. So five years go by, no one’s found the easter egg and — there are three keys in order to get to the easter egg — he’s the first one to find the first key. So his avatar becomes famous in the video game, where in the real world he’s still kind of this loser, so he’s juggling both.

And since it’s a virtual world, everything in the OASIS was shot using motion-capture.

We shot for the first seven, eight weeks in Mo-Cap. Everything that happens in The Oasis is all shot in motion capture.

Inside the OASIS, you have a personalized avatar that won’t look like you — hence the mo-cap effects. When asked whether he’d had the opportunity to help with the design of Parzival, Sheridan said he still had no idea what his alter-ego would look like.

No, that’s still kind of a mystery to me. I don’t know what the Avatar looks like, but I’ve heard that it doesn’t look like myself.

Ready Player One also stars Mark Rylance, Simon Pegg, Olivia Cooke, T.J. Miller, and Ben Mendelsohn, and hits theaters March 30, 2018.