The funniest part of the Unreal demo is not, that some people think it's gameplay. It was something else.

The insanely funny part was this guy. His role was to hold a controller while a pre-rendered cutscene was playing.

When you look back at the demo, and even if I assume, that 100% of the initial walking was actual gameplay, his role was to walk 20m, before his control was taken away.