Use a utility like WinRAR or 7-Zip to unpack the files.
This report examines Grandma's House Version 0.60 , specifically focusing on the "Part 4" content segment of this adult-oriented visual novel developed by Overview of Version 0.60 Grandmas House Version 0.60 Part 4
Grandmas House [0.68] - Download + Walkthrough - [PC/Android] Use a utility like WinRAR or 7-Zip to unpack the files