Of course they set it to play Darude's Sandstorm...
Factorio is one of those Minecraft-esque construction games that have all the tools available for people much smarter than myself to make incredible things. DaveMcW, for example built a massive complex, composed of a display, memory, and decoder sections, then replicated it via Blueprint 10 times to make a 178?100 pixel display with a total of 34MB of memory. Then he played Darude's Sandstorm on it. Check it out in the video to the right.
What's really impressive about DaveMcW's feat is that Factorio doesn't have much built-in code interpretation, so the whole thing was mainly coded in Assembly. Also, while his video studio is playing Sandstorm in the video, it can theoretically play any video.
If you're interested in Dave's design, or other crazy things people have built in Factorio, be sure to check out his thread on the official forums where he goes into more detail.
Source: Factorio Forums