PC version Fans have made a PC version. Some are still early, so read the project page first.
Fans took Castlevania 64 Recompilation 2 apart and rebuilt it so it runs natively on a computer, often with widescreen, higher frame rates and mods. Here is the project we know about:
A native Castlevania 64 PC recompilation port featuring unlocked high-framerate performance, stable widescreen support, and custom texture pack modding.