The .zip extension indicates a compressed archive. For a file named specifically like this, it usually contains:
Always run the .zip file through a scanner like VirusTotal before extracting. SuburbanDemonMother-Version1-pc.zip
Because files with these naming conventions are often shared on third-party forums or file-hosting sites, it is important to follow standard safety protocols: SuburbanDemonMother-Version1-pc.zip
An .exe file (on Windows) used to launch the game. SuburbanDemonMother-Version1-pc.zip
Sometimes, heuristic scanners flag indie games as "Unknown." If you trust the source, you may need to add the game folder to your antivirus exclusion list.