PC versionArcade Fans have made a PC version. Some are still early, so read the project page first.
Fans took Metal Slug 3 apart and rebuilt it so it runs natively on a computer, often with widescreen, higher frame rates and mods. Here is the project we know about:
Native Windows port of Metal Slug 3 (Neo Geo) by static 68000 recompilation, verified against MAME. Bring your own copy: no game data included.