I got to say, i was not a fan of the whole walking-simulator genre, and i'm totally not a horror kinda guy, but Amnesia: The Dark Descent was a great game! It made me like the genre and was fun and challenging with the sanity system and all that... A Machine for Pigs, sadly has nothing left from the first one, except maybe some assets and that it's a walking simulator... The story was boring and bland, and the overall gameplay is boring... you walk around, reaaaally slowly, and retrace your steps some times, slowly... but as you delve deeper into the game, there's no actual challenge, the puzzles are way simpler and the enemies area almost not present, and when they are are easily circumvented... there's never that gnawing feeling of the shadow from A:DD All in all, it's a boring game, that makes me want to have amnesia and forget about it...
