For those who may not know, Metal Slug Complete is a classic run-and-gun action game that was originally released in 2007, and it's a compilation of the first four Metal Slug games.
Here are a few methods that might work:
Now, about that unlimited credits cheat... metal slug complete pc unlimited credits work
You're looking for a way to get unlimited credits in Metal Slug Complete on PC! For those who may not know, Metal Slug