Basically Demise but on the actual source engine, I decided to get Bandicam on my other computer, as it can actually run Mario's Madness, and I had also switched the crappy keyboard out for the better one to do this.
This song's chart is pretty brutal, especially the last section, not to mention that BF sings quite a bit too thus giving you quite a bit of notes to hit. A challenging yet fun chart imo. I honestly feel like Hellish Heights should've been the final world in the game, don't get me wrong I really like Classified Castle and it should definitely stay, but I do feel like it probably should've switched positions with Hellish Heights, as Mario's Madness is infamous for having creepypastas mostly, and having Demise be the final song before All-Stars, it would've been a great final challenge to the player as a "If you can make it through this, then you're ready for the finale" type of thing, but that's all just my opinion.
I had also turned off the TV Filter and turned on Middlescroll in the settings, since trust me playing on the left side is harder than it seems, at least to me, and the TV Filter does make the notes a bit hard to see, especially the left ones, but that is most likely just a skill issue on my part.
Overall I don't think I did too bad here, I did get more misses than last time, but this input system isn't as forgiving as Psych Engine's
Last thought, although unrelated to Mario's Madness, but imagine MX in M.u.g.e.n, this absolute beast just smacking characters around.