Metal Slug 2 (because you have X). Metal Slug Advance (not in this bundle; that’s a GBA spin-off).
Here's a breakdown of the games included in the collection: Metal Slug Collection 1-2-3-4-5-6-7-X PC Comple...
The Metal Slug Collection, available for PC, includes games 1-7, as well as the X (or "Metal Slug X") version of the first game. This collection offers an unprecedented opportunity for fans to experience the entire series in one convenient package. Metal Slug 2 (because you have X)
The Metal Slug series debuted in 1996, developed by SNK (now known as SNK Playmore). The first game was released as an arcade title and quickly gained popularity for its challenging gameplay, colorful graphics, and quirky characters. Since then, the series has grown to include numerous sequels, spin-offs, and updates, with the most recent mainline installment, Metal Slug 7, released in 2008. This collection offers an unprecedented opportunity for fans
If you are looking for modern, standalone versions with better features like online play or infinite credits, they are widely available across several storefronts: Metal Slug Collection PC | SNK Wiki | Fandom