I actually got Battletoads as a kid when it came out for the NES. It is definitely one of the more difficult games made, and even though I considered myself to be pretty good at it, I could never get past level 10 I believe it was. Awesome game though. You should try Ghosts 'n Goblins. It makes Battletoads seems simple in comparison.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell