The game is a CIA recruitment tool.
Whoever gets the highest scores are recruited by the CIA...whether they like it or not.- Why would the CIA recruit members based on their gaming skills of all things? Also, I'm pretty sure you're allowed to say no.
- Maybe the game had to do with testing problem solving skills (and the harder the levels testing how high the problem-solving abilities can go in addition to how quick a person processes the challenge), which could potentially be used (as for what, hard to know). And also, the CIA has had no problems with illegally doing things to people without their permission (see MKUltra as an example).
The AVGN version of Polybius is actually powered with the power of belief.
The "What if it's real?" line from Nerd actually began to help the machine's supernatural powers increase, and the audience's belief on the legend powered it up.