You can unlock the ultra-hard "1999 Mode" immediately by entering the Konami Code (Up, Up, Down, Down, Left, Right, Left, Right, B, A) at the main menu.
It would be irresponsible not to mention the obvious: Repacks like Mr DJ’s are unauthorized copies. While the BioShock series is frequently on sale for $7.49 on Steam, the repack persists for reasons of convenience, not just cost. You can unlock the ultra-hard "1999 Mode" immediately
Specific weapon skins and damage upgrades, such as the China Broom Shotgun and Bird’s Eye Sniper Rifle. Early Bird Special Pack: You can unlock the ultra-hard "1999 Mode" immediately