I watch a streamer who mastered speed running dozens of NES games. He says Battletoads was the hardest game to learn. Just getting through the game, not even pushing for a fast time, was extremely challenging. Much harder than TMNT 1 or Ninja Gaiden.
Yeah, for all the difficulty I had with the dam on NES TMNT as a kid, I saw a streamer do it last year I think (I believe on first attempt?) not realizing it was supposed to be difficult. Blew my mind.
Child me could beat it after hours of repeated attempts and running out of continues.
Adult me went back after a decade. The muscle memory was still there and I beat it on the first try. I probably got about an 80% success rate on first attempts now. But level 4 and beyond I'm terrible.
My brother and I played the game so much we were able to beat that stage co-op. It gets much worse later. I learned not that long ago that the reason we were never able to beat it co-op is there's a bug that prevents the 11th stage from being beatable with two players.
I need to find an emulated version of this. Mine was faulty and always glitches as soon as you finished this stage so I never got to see neyond it for more than a few seconds. I've always wondered what was there!
Fun fact: that's one of the easiest levels in the game. It barely cracks the top 10 hardest levels in a game with 12 levels, and only because the first 2 are trivial to lull you into a false sense of security.