When it comes down to popular video game genres of the early 90’s there is no question that run and gun video games were big during that time. We had games such as Contra III: The Alien Wars along with the first three Mega Man X titles which were big attractions in countries like America following their respective releases. As far as underrated 2D run as gun shooting games are concerned the original Metal Slug game that first appeared in Japanese arcade centers in April 1996 is considered to be a classic. While Metal Slug: Super Vehicle 001 eventually came to America for the Neo Geo the PS1 port of the game had remained a Japanese exclusive following its release in the Summer of ’97.
By 1997, 2D gaming in general was starting to get old to many gamers. On consoles such as the PS1, Nintendo 64 and the Sega Dreamcast many people were starting to become more obsessed with 3D games such as Metal Gear Solid, Tekken, Soul Calibur, Tomb Raider and many others between the mid to late 90’s. If the Metal Slug series began a few years before it did sometime between 1990-1991 it could have definitely competed with the likes of the Contra and the Mega Man series during the early 90’s. But since the original Neo Geo home console was priced around $650 following its release back in back in 1990 its unlikely that too many people in America would have had a chance to play it at all. But making the PS1 port of the original Metal Slug game a Japanese exclusive was probably the best thing to do in the mid 90’s overall.