Castlevania: Nocturne in the Moonlight
Ports of games are common enough -- the original Castlevania had several ports to the various computer systems, as well as a substantive re-imagining with Vampire Killer. With the rousing success of Symphony of the Night in Japan, Konami took the opportunity to port the game from the PSX to another contemporary system at the time, the Sega Saturn. Titled the same as its PlayStation counterpart in Japan, Akumajo Dracula X: Gekka no Yasokyoku, translated as "Demon Castle Dracula X: Nocturne in the Moonlight", this edition of the game is known in Western circles as Castlevania: Nocturne in the Moonlight to differentiate it from the initial PlayStation release.
For various reasons, though, Nocturne in the Moonlight was a flawed port. The Saturn was not a compatible piece of hardware with the PSX so compromises had to be made for the game. Transparencies, for one, were not something the Saturn could reproduce, so various transparent effects from the original game were done with dithered sprites ("checkerboard" effects that end up looking pixelated). Some items that used transparency, such as the Invisibility Cloak, were replaced with other, functionally similar items that lacked the transparent effect entirely. Coloring was also off, making the game look subtly different, and not in a good way.
The aspect ratios for the two games were different, too. To compensate, the sprites were compressed, and then stretched to adjust for the different vertical and horizontal dimensions, leading the sprites to look fuzzier, more aliased, and less crisp. While it might have been better to redraw the sprites for this different system, the third-party that handled the port didn't have the resources to handle that level of work on the project, thus the reasoning for these compromises. Over all, these changes made the port feel inferior to its PlayStation progenitor.
Worse, though, was simply that the Saturn was not well-designed for 3D graphic effects. Although the PSX Symphony was a 2D game, it used the 3D engine of the underlying system to create many stylistic effects. These artistic flourishes, for whatever reason, were kept in the Saturn edition, but due to the limitations of the hardware they caused severe slowdown whenever the flourishes appeared on-screen (including in the single-screen save rooms). This was coupled with much longer load times for areas (and menus, and maps), which slowed down the entire pace of the game substantially.
For all of these reasons, the general opinion (among reviewers and fans) was that the game was a hobbled port of the original game; the Saturn was just not capable of being a PSX, and it showed. Even if the original release of Symphony of the Night had been a sales success in the U.S. (which it wasn't, not initially), it's doubtful this version of the game would have come overseas. Between it being a reviled port of a fantastic game, on top of the Saturn also not being a huge success in the U.S. and abroad (it did sell well in Japan, its home country, but that was about the only region that embraced it), it had almost chance of finding an audience in the United States. A port to the XBox would have been more feasible for the West, but the XBox wasn't at all popular in Japan. Thus, this port was doomed to remain an Japan-exclusive.
Even when re-releases of Symphony of the Night were developed for a worldwide audience, the Saturn version, and is many additions to the base game, was ignored in favor of crafting a new, and expanded, version of the PlayStation edition going forward.
Additions to Nocturne in the Moonlight:
Despite the flaws, there were something additions to the Saturn package that weren't a complete loss. For starters, two new areas were added to Nocturne in the Moonlight: the "Underground Gardens" and the "Cursed Prison". Although some have commented that the new areas weren't all that necessary, and that they barely added much to the overall game (even the game itself computed percentage based on the PSX game, so these new areas changed the basic exploration percentage of the game), they were welcome additions all the same. The Gardens attached to a secret, glitched areas at the "Entrance" of the original game, and was presumably intended to be included in the original release. Meanwhile, the Cursed Prison was a set of hallways that connected the "Marble Gallery" and the "Caverns". It's a shortcut, basically, but considering the long load-times of the port, a welcome shortcut all the same.
The biggest feature, though, was the inclusion of Maria Renard as a playable character. Maria played a big part in original game, helping Alucard in his quest; here, she's granted expanded status. Interestingly, she plays differently here than in her previous appearance in Castlevania Dracula X: Rondo of Blood, with an emphasis on martial arts over flinging birds and summoning animals. This would be rectified in the next version of the game, the The Dracula X Chronicles, where her original game play style (of birds and animals) would be restored.
As a further bonus in this Saturn port, Alucard will forced to face off in battle with Maria, where she tests him before giving him a key quest item. Both unlockable characters, Maria and Richter Belmont (included again, as in the original version), are playable from the outset, too, and don't need to be unlocked. Richter also has a secret second outfit more in-line with his "villain" art from the promotional materials for the game.
Thankfully, although the Saturn port never came to the States, Maria's inclusion in the Dracula X Chronicles meant that the most essential feature of Nocturne in the Moonlight did get an international release (at least in some form).