Is this a Parallax theme with layer sliders, etc. or something else?

Hi there,

A client wants a site that is similar to this:

http://hollowdocumentary.com/

After staring at it for awhile, I think it could be accomplished using a parallax wordpress theme with layer sliders and other elements on the various parallax sections. Do you agree? If so, any suggestions on an approach (such as useful plugins or theme suggestions). If not, what do you think this website is doing to accomplish the interactive documentary feel? Thank you for your advice.

Kind regards,

AD