The NES remains one of Nintendo's biggest selling consoles of all time and one of the most popular of all retro gaming consoles.
Metal Storm was released in 1991 by IREM. It was a game that really pushed the NES to it's limits, as it features multiple levels of Parallax scrolling, that being multiple foreground and background objects that scroll at various speeds. The other gimmick revolves around your mech being able to switch around the gravity to walk on the floor and ceiling.
This is a game that shows off the true power of both the NES in terms of power and graphics, as well as the developer. Another game that fell by the wayside, due to it being released in 1991, when the world was clamouring for 16 bit graphics. But one that definitely deserves a look in, a definite challenge here.