For the retail releases of Metal Slug Collection (specifically the PC CD-ROM versions), the serial number served a specific function in the installation wizard:
If you’ve come across an old copy of Metal Slug Collection for PC (often packaged as Metal Slug Complete PC or Metal Slug Collection: Ultimate Shooting ) or are trying to install a second-hand copy, you may have encountered a request for a (also called a CD key or product key). metal slug collection pc serial number
: Offers DRM-free versions of several titles in the series, meaning once you buy them, they don't require an online check or a serial key to run. SNK 40th Anniversary Collection For the retail releases of Metal Slug Collection
