If you are using a computer when playing this I would recommend using visual boy it emulates game boy advance games very well now if you are playing on your phone I would recommend the my boy emulator it works very well on the phone if you are playing on something else though I would talk to others on here about that they could help you
My Castlevania Ninja hack is on the move again thank you to everyone who is helping me with this hack it's really appreciated
Well, I was at least able to get the game to still work after inputting the code thanks to your provided rom inside the rar. I wonder why the other one from the link in the original post was broken. Thank you!