Speaking of the soundtrack, before Virt (Jake Kaufman) made it big (composer behind Shantae, Shovel Knight, Ducktales Remastered, a few others), he made this: https://www.youtube.com/watch?v=5uEUImofSms

"Bogey at your 6", the combat theme from the game, but remixed as if Konami had made it for the VRC6, the NES mapper chip that added 3 additional oscillators that made the Japanese release of Castlevania III what it was; he made this using Scream Tracker (or possibly a newer tracker, but its saved in S3M format), because tracker-like chip emulators didn't exist yet (Furnace, et al).