If you are reading this, chances are you bought a used copy from a garage sale, or you lost the original key over a decade of hard drive crashes. You are staring at the installer, and it asks for that cursed string of letters and numbers.
The Metal Slug series, originally developed by Nazca and SNK for the Neo Geo MVS arcade systems, eventually found its way to the PC through several iterations: metal slug collection pc serial number
If you own a legitimate copy but can't find the key, check these common locations: If you are reading this, chances are you