Dark background. Sweet jazzy opening music. First person narration. Rain pounding on the windows. Early entrance by a femme fatale… who is actually your business partner, not to mention (Spoiler - click to show)a succubus - the ultimate femme fatale! - and who totally calls your bluff on pretending to be asleep. With all of this, plus the title, I’m thinking that Grimnoir is going to be a noir detective story that nevertheless plays with noir’s usual tropes. And, sure enough, that’s what it is.
One major aspect of the game perhaps takes noir in a different direction rather than playing with its tropes. This is the fact that (Spoiler - click to show)the PC specializes in the supernatural - particularly tracking down various undead spirits. There are probably other works that feature this as well, but I was reminded of Jonathan Stroud's Lockwood & Co. series of novels.
A second aspect is truly playing with noir’s tropes. As you slowly come to realize over the course of the game, (Spoiler - click to show)the detective PC is gay. This affects the story and gameplay some, as it makes him immune to the charms of his succubus partner, while leaving him susceptible to an incubus in one of the mid-to-late-game cases.
Gameplay involves solving a series of cases. You're given three cases initially that you can investigate in any order. After you complete those you're given three more cases that you can investigate in any order, followed by the endgame case(s). (It's kind of like Detectiveland doubled, in that respect.) Three cases at a time gives the player some choice without it feeling overwhelming in the way six or seven cases might.
The player also has access to the Grimnoir, which contains a list of monsters and their powers. This was fun and reminded me of a miniature Dungeons & Dragons monster manual.
The cases feature some interesting narrative and investigate variations. For example, (Spoiler - click to show)in one case you play as the succubus partner, which was fun partly for variety and partly because she has cool powers. In addition, another case involves two spirits rather than one.
My one gameplay critique has to do with your selection of the monster that you think is causing the crime. After you've completed your investigation, the game gives you a list of three monsters to choose from. With only three names it’s easy (if you remembered to save just before the monster encounter) to try all of them and then reload if you’re wrong.
Also, from a narrative standpoint I’m not sure why naming a monster would cause it to freeze, although from a gameplay standpoint I can understand this: The game needs some way for the selection of the monster type to be decisive in terms of the investigation, and having the monster freeze when named accomplishes that.
The final case is a nice wrap-up of the PC's storyline and series of investigations.
Overall, I enjoyed Grimnoir. It's a well-done noir homage that nevertheless plays with its tropes in interesting ways.