While finding original cartridges can be a challenge, several modern ways exist to experience this retro gem for free: The Castle (SG-1000, 1986) - Sega Does
Originally developed for the MSX and later ported to systems like the SG-1000 and PC-88, The Castle is known for its slow, deliberate pacing and reliance on resource management. Your primary goal is navigating a non-linear map, pushing blocks, and collecting a staggering variety of colored keys to unlock matching doors. The Castle Free Download
: Long before "Metroidvania" was a term, The Castle utilized a large-scale map and item-based progression that felt years ahead of its time. Where to Play "The Castle" Today While finding original cartridges can be a challenge,
Revisiting a Retro Classic: The 1986 Challenge of "The Castle" The Castle Free Download