There are many reasons to play ASA if you like Adventure games.
One of them is this list of reviews, with an average rating of 15/20 in the press online.
Another good one is that most of the players who were fans of Myst or Rhem enjoyed this game and even asked for a sequel !
You could also play it because you're interested in TBT: The Black Tower, my next indie game, which will have a link with the story of ASA.
But today, the main reason is that ASA is on sale !