Love this game it is very entertaining, I play if for hours with my wife. You can think of this game as a mix between Zelda and Battletoads, the graphics aren't great. This game is quite funny as well, You can pickup brass knuckles and chains a beat each other up just for fun. Anyone can play it, though it can get confusing on how you progress to the next boss.
Passwords make it possible to continue where you left off.
Overall I think its one of those great classics that never got the notice it deserved.