Have you played this MYSTerious game?

Or perhaps it\'s sequels? Riven, Exile, or Revelation?

I played the original on Sega Saturn a long time ago. I liked it, but I had no clue what I was doing! I was pretty stupid with videogames back then. I could play it again since I still have the game, but it\'s messed up and I don\'t know why. There isn\'t a scratch on the disc, as far as I remember, anyways.