No installation necessary.

After downloading upzip file.

Copy X-Men The Ravages of Apocalypse folder to your computer.
Open X-Men The Ravages of Apocalypse folder.

Find the application executable file, darkplaces.
Click on the darkplaces file to start game.

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Create a shortcut to make starting the game easier.

Right mouse click on darkplaces file and Create shortcut.

Then copy X-Men The Ravages of Apocalypse short cut to Desktop.

Click on short cut to play X-Men The Ravages of Apocalypse

You can rename short cut to X-Men The Ravages of Apocalypse

Finish.