Once extracted, open the folder. Look for an application file (e.g., Cz_party.exe or Game.exe ).
: If you get a "Can not open file as archive" error, the download likely failed or was cut short. Try downloading it again. Cz party.7z
If it is a Ren'Py game (common for this file naming style), you may see a .sh file for Linux or a .app for Mac. Once extracted, open the folder