I'm not entirely sure just how far the term "Coin-Op Conversion" goes. In some cases we get pretty straightforward conversions with obviously degraded graphics (think Ghosts'n'Goblins) in others there's also omission of some features available in the Arcade game (like Turtles in Time, for example).

But there are cases when Arcade and console versions are really different. Like this game. To anyone who's reading this - just watch these two videos and compare. I see obvious differences between versions, which makes me think that NES game is not a conversion, but a standalone product specifically developed for home console.

Just to name a few - switching between 2 planes in Arcade version, different levels, and generally - different game mechanics, art etc.

NES: http://www.youtube.com/watch?v=VYrvwCRTI7o

Arcade: http://www.youtube.com/watch?v=dXov_6JNkAQ

So, is it really a coin-op conversion?

I think a game entry should only receive the coin-op conversion genre if the arcade version would be grouped under the same entry.

But we are far from consensus regarding when a game should be split and when it should be lumped.

That's a terrible idea.

This is pretty obviously a conversion. They had to make (a lot) of concessions to the hardware, but they were trying to make the same game.

How can you call the result the same game when its obviously not?

power ups are the same, controls are the same, most of the same monsters, you still have to destroy monsters to move forward, same princess to save, same armor, mostly the same castle design. That's why this is a conversion, and not a port.

What about being able to go closer to the screen and further which adds another dimension to the gameplay? What about item management (lots of different items everywhere in ARC and very scarce items in NES, where you need to learn it all by heart). And armor... isn't really the same. Having played both versions the only "sameness" I found was boss music and final boss' design.

And it plays very differently. It's like Astyanax - another coin-op conversion wannabe - totally different. I wonder what are criteria for "coin-op conversion" tag.

I would say a shared name and a legitimate use of the license.

Well the arcade parent for Castle of Dragon was named Dragon Unit.

in Japan. Which was also the title of the NES game's Japanese version.

Yeah, remembered that myself after I replied.