On PC, the situation has been historically messy. There is no single "official" Steam page called "Metal Slug Collection" in the West. Instead, individual ports exist (like Metal Slug 3 on Steam) alongside the (a compilation released in the mid-2000s on CD-ROM).
The old CD-ROM version of Metal Slug Collection PC often suffers from "DirectInput" issues, meaning modern Xbox or PlayStation controllers don't work out of the box. metal slug collection pc link
