Something on the screen is going right. That is Hardpack Rally he is playing, and partway through he turns round and tells you about it. Drop in a voice clip and he says yours — the mouth follows the recording. Add a tune if you want one under it. Nothing leaves your device.
The screen is playing Hardpack Rally, with its
own sound — and you can drop any video in there instead. He stops typing once the shot is about the
game, so you can hear it. The export runs in real time rather than as fast as it can, because
that is the only way the video on the monitor is really playing in the file. The desk and the man are
generated in Blender by hype-src/build.py; there is no .blend anywhere.