Castlevania, released nearly 40 years ago on the Famicom Disk System, has become a favorite among speedrunners. Recently, one of them discovered the game’s “ultimate” glitch. SBDWolf found a way to warp directly to the end credits from the game’s tenth level, roughly halfway through, cutting the speedrun record almost in half. YouTuber Karl Jobst has created an excellent video demonstrating the process, which begins with a staircase glitch in level ten.
You can try the glitch for yourself on your Ultimate MiSTer running the Nintendo Entertainment System/Famicom core, with FDS support!