User blog comment:Vorred/Mata Nui Online Game III - Destinies Announcement!/@comment-15501857-20141103153622/@comment-5174759-20141103154812

The file is a .zip file. You need either 7zip or WinRar to open it, which are both free to download. You then right-click it, select "7zip/Winrar" and selecte "Extract files".

This will create a new folder with all the game files in it. Double-click on the MNOG3D_PreAlpha.exe and run it.