This game has only just recently been devised, so only high-rollers would know anything about it. Before the games have started, there will only be rumours and small amounts of tabloid speculation with no evidence of any sort to support them. Only major-level hackers will have any information about it, but even then they can't really say much about it. Once the games have ended, they will be about as well known as underground fighting rings in that the general public won't know much about them except for the fact that they exist. The events of the games will be recorded live and uploaded to a website that can be accessed by only those with the right security clearance. In other words, it's basically an underground reality show that's seen by the same sort of people who plays backroom poker, bet on dog-fights, and attend black-market auctions, except it's all of them all around the world combined. Everyone above entry-level within one of OROCHI's many companies will also have access to the website. Due to the website's abnormal security, the number of people who can hack into it can be counted on one hand.
The only way a player could have any concrete prior knowledge about the games is if he/she has an extensive criminal background of some sort, is friends with someone who'd have insider information, or already an employee of one of OROCHI's many companies.