bought it, played it, really liked it (PS: if you like, I can trade you a steam key of this game for Ittle Dew for GOG, see Classifieds)
indeed, this game is nothing more than an interactive story, where you walk around a big house and search for notes, postcards, books, journals and other documents from which you learn about the members of the family (and, of course, their problems and what they tell / don't tell)
the most fun for me was the fact that you REALLY NEED to search everything, look behind sofas, under the pillows, between shelves, and as I'm obsessed with searching every corner in all the games anyway, I loved that you actually find A LOT of hidden messages if you do... of course, if you don't like scavenger hunts so much, you'll probably only find half of the documents and the story might not work or seem very shallow...
but as I said, I liked the game - the abandoned house in the storm has a great atmosphere, and I was really looking forward to find out more and more about the family - and as I read somewhere, "at the end you feel like the house and the family living in it are real"
can't really think of any other game to compare it to, so hopefully the info above will give you the idea if you want to experience this or not :) I was satisfied and don't feel sorry for the money spent.