Castlevania 3 has been a troublesome game for clone systems. Only recently has there been a breakthrough. Most still cannot play the game. There are about 23 games in the NES library that clone systems will not boot, or play. Castlevania 3 has been on that list as is Rad Racer 2, and my Gauntlet. My Gauntlet game will boot, but the graphics are rearranged in the first board. You cannot finish that board because of that.
Clone systems have been backward engineered to mimic the original hardware. They are not perfect and they do not necessarily play the games perfectly . But I find it interesting just how close they are getting. These latest Hyperkin consoles are great for the budget minded gamer wanting their retro gaming on an HD TV. They offer the best option for those who can't afford the more expensive route. You just have to overlook that maybe some sound effects might be in a higher pitch, music a little off, graphics might be a different tint, or completely different colors. But the game still plays the same.