Very clunky, and feels quite old for the year it's been made... it's quite odd that you can murder someone in the middle of the street and then run about 10 seconds away and not face any repercussions. The mechanics aren't fantastic either... and the load times for entering buildings seem so out of place in this close of the decade title. A lot of the scenery is quite obviously recycled, to the point where I'm sometimes unsure whether or not I've been somewhere or not.
HOWEVER! The story line and the atmosphere are really genuinely good. The universe is also impressively true to H.P Lovecrafts vision, doing well to make reference to his lore while developing lore for the game independantly.
I love the fact that the entire game is self directed, no pointers at all so you have to figure it all out yourself. Like a true detective. Given a sequel, this game could really shine with a better engine, and new mechanics (Perhaps like the ones present in L.A Noir, regarding dialogue.) And a more fleshed out mind palace with further options for making deductions would be awesome.
Over all I would grade the game about 7/10, since the recycled scenery and bad mechanics could be referred to as an eldritch horror of its own, but the story and the atmosphere really shine through.