If by "paper" you meant a whitepaper or research paper about the game's development, the series is widely documented on Wikipedia as a "neo-noir" third-person shooter inspired by film noir and titles like Max Payne .
Passwords are often found on the website where you originally downloaded the file.
If you need documentation to understand how to play, you can find official manuals online:
: A 24-page English manual available on Scribd.
: The most common tool for this format. You can right-click the file and select "Extract Here" once installed.