Retro Game of the Day! Metal Slug
Metal Slug by Nazca, published by SNK. First appearance (and most famously) on the Neo Geo console in 1996. A true classic!
So what's the story here? Nazca, as the story goes, was made up of former Irem (R-Type) folks, this is evident in looking at the game In The Hunt (similar basic art style to Metal Slug). Furthermore, the Gun Force series (especially #2) looks like a direct ancestor to MS, both in graphical style and actual gameplay. Whereas Gun Force was more of a straight-take on the Run 'n Gun genre, MS opted for a much cartoonier style and theme-
MS is an homage to Contra through and through, lovingly hand-drawn and animated in a way that no game had been done before or since. Though they took a tired and somewhat out-of-style game convention, the new look and attention to detail completely reinvigorated this genre (if only for this particular series) and instantly made MS a staple for the gaming community. The audio is notable as well, jazzy and bouncy orchestrations that match the onscreen action (and style) note-for-note.
As noted, the game is a Contra derivative, you command a single soldier (or team up with a buddy) to take on the Evil Enemy Army and save the Free World. You are armed with a standard pistol, a knife (slash enemies up close), and a limited supply of grenades for long-distance damage. Very often you will rescue POWs who will grant you limited ammo super-weapons such as the flamethrower, heavy machinegun, or rocket lawnchair (the accent of the narrator's voice is hilarious!). Each super-weapon is likewise beautifully animated and gives the player a real sense of having a profound advantage against the endless barrage of enemy soldiers.
The game takes it's name from the Metal Slug - Super Vehicle 001, a tank that occasionally appears which the player can jump into - again for a distinct advantage over the enemy, the vehicle is scrappy and agile (it reminds me of the tank Bonaparte from the old manga "Dominion Tank Police") and it's very enjoyable to control. Further iterations of the game played up this whole "vehicle manipulation idea" with not just the tank, but also pilotable submarines, aircraft, spaceships, and camels (!)
Overall MS is a venerable series which has long outlasted the hardware that spawned it, while maintaining the same style which is has been famous for all these years. At this point the game has spawned 7 direct sequels (and a series of side stories) and we'll see where it goes from there!