As stated by the author, “Monotone Museum was actually created as an example of how someone with no previous game design experience–namely Sugano Tasuke, an illustrator–could easily make their own tabletop RPG using SRS” (SRS is a popular Tabletop RPG engine in Japan, somewhat similar to the d20 system in the West)
This release is considered the “final” release by the translator and contains translations for things such as the background setting and a “replay” (transcript of a sample game), but no game rules.
Why? In his own words “Since underneath the fluff SRS is nigh-identical in every game that uses it, you can just use the rules from another F.E.A.R. title like Double Cross or Night Wizard if you want to experience Monotone Museum in something pretty close to its original form.”
You can download the translation here.