Try entering the key both with and without the dashes. 2. The Installer Won't Launch (Modern Windows 10/11)
For many, this collection represents the golden era of the franchise, offering the core arcade experience with its iconic pixel-art graphics, frantic gameplay, and signature vehicles, all without the censorship found in some later ports.
A quick look at search results for "metal slug pc collection serial number" reveals a common narrative. One answer from a question-and-answer site highlights the core issue: "You can't get the Metal Slug PC Collection serial number without registering the video game through the Internet; most people who want this number need it because they've downloaded the game illegally, and they have the torrent, but no serial number to get the game up and running".
If you need help getting a specific version of the game to work, let me know: