I can understand why ratings for this game might be mixed, this is some kind of "you love" or "you hate" game.
But I'll explain why I loved it myself: This FMV (Full motion video) game is very simple but effective. You can compare it to a jigsaw: Videos from police interviews regarding a disappearance have been cut to pieces and you have to find all the pieces and put them together to understand what really happened. To find these pieces, you have to look for terms in a search engine, the first one is given to you. By viewing the part of the interview linked to that search term, you can discover new terms to look for, like names, locations and view more parts to work on...
Piece after piece, the "picture" (the story) becomes clear. The game is over when you've looked at enough videos to understand the story. It's a very interesting and relaxing game, the scenario is great, the acting is convincing and uncovering the story piece by piece in a random order gives it a lot more interest, you feel a lot more involved in it.
Regarding achievements, these can be obtained in a few hours by finishing the game and look for the remaining missing pieces. Once you've uncovered all, your completionist needs will be fulfilled.
4.0