This game is incredibly well put together.
If you enjoy sidescollers this one has all the elements of the games you loved. Rolling like Samus or Sonic, pewing like MegaMan or Bubble Bobble, Balloon Floating, Bird riding...
All of this expertly programmed into the same space as Mario? It's incredible. No slowdown, or input lag. It's the most fun I've had with the NES in ages and someone I know already summed it up better if I can steal the words from a friend "Rollie is baller, Everyone should own this."
It was available on an actual NES cart, with manual and box, something I never experienced as a kid at christmas, that was pretty cool.