Fancy giving yourself a seriously difficult first run at BioShock Infinite? You probably don't, but the option is available to unlock from the off.

All you need to access the game's rock hard 1999 Mode is to enter the famous Konami code on the game's main menu. That's: Up, Up, Down, Down, Left, Right, Left, Right, B and A.

PlayStation 3 players should substitute the last two buttons with O and X.

1999 Mode is usually only unlocked after completing the game.

Amusingly, it's exactly how BioShock Infinite creator previously promised the mode wouldn't be unlocked, Game Informer, which discovered this method, reported.

The developer then said it was "talking about" such a method, but had not confirmed its inclusion.

"Probably what we're going to do is you'll only be able to get to that mode through some kind of unlock," Levine said last year. "Not unlock in the game through 'left, right, up, down' that kind of thing."

1999 Mode is so named because it harks back to the more hardcore shooters of the nineties. 1999 was also the year that BioShock developer Irrational's System Shock 2 released.

"One of the reasons 1999 Mode is so much more difficult than any other setting is that dying often uses up all your money and then you can't respawn," Tom Bramwell wrote in Eurogamer's 10/10 BioShock Infinite review.

"You're sent back to the main menu and have to resume from your last autosave prior to the section where you died."

A new infographic released by Irrational via its Twitter account revealed that the game features over 10,000 lines of dialogue, a third of which belongs to main characters Booker and Elizabeth.