What kind of games does Text Fiction play?
Currently, Text Fiction only plays Z-Code games conforming to Z-Machine 3, 5 and 8 standard. Files must have the .z3, z5, z8 or .zblorb extension and be placed in your "Downloads" folder in order for Text Fiction to find and import them.
Note: The filename suffix only matters to the import tool and you are not required to use it. It is perfectly ok to use a filemanager app or your Desktop computer to manually copy game files into the game folder.