Basically, Pyramid 2000 substitutes a pyramid for the building in Colossal Cave, replaces the high fantasy gingerbreading with Egyptian mythology, and manages to cram a substantial portion of the classic treasure-hunting experience into 16K of cassette-loaded RAM. I finally solved Pyramid 2000 with the help of Tandy's support line, but only discovered a few years later (on a friend's Apple II), as a 'new' adventure became increasingly familiar, that Pyramid 2000 was actually an excerpt of the Crowther and Woods Colossal Cave Adventure, redressed with an Egyptian theme. The pyramid motif was more enduring, and many later adventure games explored similar settings. The game's manual was a product of the late 1970s, positing that our adventuring avatar is a product of Astral Projection, a New Age concept since consigned to the pop culture dustbin.