The keyword "Metal Slug Collection 1-2-3-4-5-6-7-X" specifically denotes the core mainline entries of the franchise, excluding spin-offs like Metal Slug 3D or Metal Slug Defense . Here is the breakdown:
The most stable way to play is through Steam. SNK has released high-quality ports of: Metal Slug Collection 1-2-3-4-5-6-7-X PC Comple...
When gamers type the phrase into a search engine, they are looking for a Holy Grail: a single digital package that contains every 2D classic from SNK. Bringing these titles to PC via various "Collection"
Bringing these titles to PC via various "Collection" bundles has allowed a new generation of soldiers to experience the madness without carrying a pocket full of quarters. The Foundation: Metal Slug 1, 2, & X Metal Slug Wiki Gameplay Overview
: Metal Slug is best played with a friend. The PC collection allows you to team up for local couch co-op, just like the old days at the arcade. Metal Slug Wiki Gameplay Overview