The developers at Innerloop Studios included a built-in debug cheat to unlock the instantly. This works on the retail CD version, the digital re-release on GOG.com, and the original PC disc.

Download a from a trusted gaming archive online.

If the keyboard cheat code fails to register due to your operating system or game version, you can manually unlock the levels by modifying a single configuration file in the game directory. Step-by-Step Instructions

Type slowly on your keyboard. (You won’t see a text box; just type it).

Here are the to unlock all missions in Project IGI 1.

: Open the folder named pc and look for a file named CONFIG.QVM or a similar configuration file depending on your specific game patch.

The Absolute Best Method: Using the Mission Unlock Cheat Code

: Right-click network.cfg and choose Open With > Notepad .