These are versions of the game that have been released to the public. There are of course other releases such as pirate copies/compilations and preview/demo copies in which various aspects of the game may be different, some of which may be found listed in the Collectables section.

"The creators of the famous 'Shining' series of adventure games, Team Sonic, return with their best and most advanced game yet. A gripping good versus evil storyline, massive quest, great 3D graphics, excellent fighting action and puzzles-a-plenty, make this a must for Saturn owners!"
  - from the Shining the Holy Ark box.

Shining the Holy Ark is often considered to be the big brother of Shining in the Darkness, as they're both essentially first person dungeon/labyrinth games. The graphics are lovely, the music (by Motoi Sakuraba, who also worked on Shining Force III) is very atmospheric and the game is great fun. However, if you didn't like Shining in the Darkness, it's quite possible you won't like this... but, you do get to see all the attacks in glorious 3D!

Shining the Holy Ark has a great plot too, linking in with Shining Force III (which is set 10 years after Holy Ark), but there's really too much to go into here. I suggest you play the game (it's not too hard to find and not too pricey) or read on it at one of the sites listed here at SFC.