Project '06 (P-06) is a fangame created by chaosX that rebuilds the original game, but it does not include game assets.
You will need the Marathon Recompiled tool to create the PC port from your own legally acquired Xbox 360 files. P06.7z
To "create" or set up this piece, you are likely looking for the tools to compile or install the project, specifically . Here is how to proceed: Project '06 (P-06) is a fangame created by