Here's the roms on DVD-
http://www.allmyroms.com/freemameroms.htmNeither the Megadrive nor Supergrafx games were real ports, they are more like conversions.
Most of the art/graphics of the MD version is original/redrawn(simplified), like the SMS game, but looks arcadey on it's own(certainly when it came out).
The Supergrafx game uses more of the arcade's graphics art, but uses very few colors and wasn't touched up very much(the game could've been ported to regular PCE
way better).
I've seen a couple message board posts detailing the ways that the MD version is better(like the crystals), but really, the SGX game is just being more faithful to the original in those aspects.
I've also read people saying that the sound sucks, but it seems more faithful(and usually just better) overall to me.
I can definately say that you can't judge it from an emulator, it looks a lot different running on real hardware.
As for the conversion VS port deal, its the same with Strider.
Try loading up both the arcade and Megadrive versions and check out every aspect of the bg's and watch the sprites. From what I remember, the MD bg's are pretty much all original(devoid of detail), I don't remember how many sprite's were faithful.
Now although most people only want to trash the ACD Strider, it actually uses bg art from the original, although it also wasn't cleaned up enough nor used anywhere near a decent ammount of color by PCE standards.
Where most sections of bg in the MD version are just a single color, there is archetecture in the ACD game.
Visually, if you
really(for real) compare the 2 'ports' to the arcade original, the Megadrive/Genesis version looks nothing like the arcade and the ACD version at least tries.
All these people who rant and rave about the 'perfect' port of GnG to SGX or the 'perfect' port of Strider to MD never even try to compare them at all. They just turn on a single game and judge it's "conversion" by how impressed they are from playing the game on it's own.
And judging by how low color and untouched the visuals in are in GnG SGX, the ACD Strider is exactly how the SGX port would've turned out with similar effort, only minus flicker with added bg scrolling.
This is why I love any port on it's own merits(worts and all) instead of how another port supposedly outdid it.