SNK eventually became known for the Neo Geo which was a game console that was basically just SNK's arcade board of the time adapted for home use. For many years it was the only system that gave you arcade perfect ports at home because they weren't ports at all, they were the same exact game. However, before all that, SNK developed arcade games on slightly more primitive hardware and ported many of those to the NES. Two of those were Ikari Warriors II: Victory Road and Iron Tank, both from around 1988.
Victory Road was the sequel to the original Ikari Warriors. In the first game your goal was to rescue a general. Both games were action games played from an overhead perspective. It was very similar to games like Commando. Victory Road introduced the relatively novel ability of being able to fire in a different direction than you were moving. In the arcade version this was accomplished with an 8-way rotary joystick. For the NES version, you moved in the direction you faced until you pressed the fire button then for as long as you held the fire button you would face that direction no matter which direction you moved. In addition to the NES version, several home computer versions were released including for the Commodore 64, Apple II and PC (DOS).
This was a pretty mediocre game really but I always found this style of game appealing. Despite the frustration, you always wanted to try to make it just a little further. Victory Road is worth checking out even if only for an afternoon. There were remakes for the PS3 and PSP but I recommend the NES version or one of the other older ports or even the original arcade version over the remakes.
The NES version of Iron Tank is based on the SNK arcade game TNK III. Like Victory Road, it is also an overhead action shooting game. However, as you might expect, you are controlling a tank instead of just a guy. The tank has two weapons, a machine gun and the main gun. The turret can be rotated and shot independent of your direction of movement. You might be noticing a theme here. There are various power-ups that can be picked up along the way to improve your weapons, restore health and so on. The unique twist with this game (besides the tank) is the ability to choose various paths throughout the game.
Iron Tank was only ever released for the NES though there were conversions of TNK III for home computers of the time such as the Commodore 64.