I have recently picked up the Lamentations of the Flame Princess "Rules and Magic" Book at The Wyvern's Tale (the friendly local game store). I have only flipped through it a couple of times and have not actually read through the rules. Though from what I have read it appears to be a D20 based system. The book itself does bare the the "18+ Explicit Content Warning". It is classified as a "Weird Fantasy" so I expect that when the Referee Book and the Bestiary comes out it will have some Lovecraftian type monsters and story elements.
The 2013 Free RPG Module "Better Than Any Man" takes place in medieval Germany. I picked it up last year but haven't had the chance to play it. The setting is incredibly dark and I find it a nice break from the fairy tale sort of settings that seem to be common in games such as "Pathfinder " (by Paizo Publishing) and Dungeons and Dragons 4e (by Wizards of the Coast). Now don't get me wrong I love both of those games and I took part of the play testing of D&D Next. But I have been yearning for a darker more gritty setting. I have been playing the Song Of Ice and Fire RPG, which accurately displays the feel and setting of the novels. In my humble opinion I find that even with a quick read of this game, it definitely gives the world a incredibly gritty feel.
All in all, I look forward to playing this game at Free RPG Day on June 21st. If you are in the Asheville Area, I will be running the 2014 Free RPG Day adventure at The Wyvern's Tale, I encourage you to join us!
Get the rules for free Here! It does not contain any of the art. So, I encourage you to go and buy the hardcover book at your FLGS so you can see the beautiful and disturbing artwork!