My Kaizo-style hardhack. No glitch abuse necessary, and I would recommend sticking it out and playing without savestates. Contains many unique, extremely difficult challenges spread across ten levels. Also has a death counter in place of the lives counter, so don't freak out when you see the "Mx0". It goes up each time you die.
Download (patch to Super Mario Bros. 3 (PRG1) [!].nes)