As shown, the file is a structured log. It is not a game itself, but rather a The "21" in the filename likely corresponds to a specific checkpoint—level 21, day 21, or save slot 21.
Alternatively, in specific online communities (particularly those centered around fictional writing or roleplay), "SS" can stand for "Short Story." However, given the numeric and naming conventions that follow, the "Screenshot" or simply a generic "Sample/Series" designation is statistically more likely. SS Lilu 21 txt