Conceptually Intriguing, Strikingly Shallow
LA Noire is more concerned with showing you everything it has to offer than demanding any critical thinking from its players. If you become engrossed in the story and just want to see unfold, this probably won't be an issue, but those looking to solve complex logical puzzles are going to be disappointed.
LA Noire does do a lot of things well. The technology on display is wonderful, accurately capturing the details of facial movement to a amazing degree of believability, and the atmospheric qualities of the painstakingly rendered 1940's Los Angeles are second to none. The issue comes from the gameplay and structure. The way you interact with this world is limited to a frustrating degree though poor implementation of shallow mechanics.
This game, of course, is not GTA, nor should it be. The violent sandbox that series is infamous for wouldn't make sense given you role as a LAPD detective. It instead finds itself in the realm of adventure games. The only problem is, it does not provide what is traditionally expected from the genre. Instead of using logic based puzzles as a roadblock that needs to be solved in order to continue, LA Noire moves forward no matter what. It guides you through the motions of an adventure game, but never lets you play for yourself. You never have to just figure something out. In fact, the game doesn't let you. It steers you in the right direction so much, it never feels like you solved a case so much as it feels the solution was presented to you. Even if you do manage to make mistakes, you are never punished for them as you can not fail. Every case ends with an arrest. Messing up an investigation by missing a clue or being a poor interrogator will only momentary set you back, as the game is sure to provide more than enough critical pathing to make sure you get your man. The harshest the game gets is grading your performance at the end with a star rating of one through five, but that superficial consequence has no bearing on anything.
The game sidestepped the adventure game problem of convoluted puzzles not by giving logical puzzles, but by giving you shallow ones instead. Shallow ones that don't require any thought from the player in order to progress, and yet the interrogation sequences still fall victim to "the script writer designed it this way, so even though this other way makes prefect sense, you can't do it" issues. As a result, everything you do feels unsatisfying on a mechanical level and it soon becomes tedium as you go through the same steps over and over. The story has some interesting threads, and the acting is best in class for a video game, but it's not enough to justify the hours you spend repeating the same empty motions. Searching a crime scene quickly devolves to bumping up on the edges of the environment waiting for the controller to rumble to indicate a possible clue. When picking up the object, your character will tell you if it's important or not, and why. It removes any any chance of approaching the cases critically and is merely a change of pacing in an interactive movie.
Interrogations are equally simplistic. Despite the subtlety the faces in the game are capable of, detecting a lie from the truth is practically binary. A stone faced gaze shows there is nothing to hide while lairs will look around nervously or smirk like morons. The only difficulty comes from deciding between a "lie" and a "doubt". Doubting is to be used when you don't have the evidence to prove dishonestly, while accusing a lie requires proof. When you choose "lie" though, the necessary support will be spelled out fairly clearly through the conversation, so it again does not require much thought on the players end. The only exception is for the times previously mentioned where things are more ambiguous, not through challenging design, but by sloppy, arbitrary decisions by the writers.
The other aspects of LA Noire are serviceable, but totally incidental and forgettable. Action sequences found in missions work, but have no intent in providing any actual depth or challenge. Street crime side quests are the same. Collectables are probably the simplest and most boring thing you can put in an open-world game, and are no exception here. The only possible redeeming quality is the story. I personally found it decently entertaining, but incredibly contrived and lacking in some regards. The characters were pretty well done, but the plot has many pacing issues and several poorly handled twists. In addition, if you do decide to use you detective skills anyway, it's likely you'll be able to call some of these curve-balls. In that case you'll probably be frustrated when you still have to let the game decide that it's time for you to know as you continue down the linear progression, forced to make choices you know don't matter, and are really quite ridiculous given the true nature of things. Your mileage may vary though.
As a piece of interactive fiction, LA Noire is still probably the best you can find today. If that's what you want, fine. But as a good game, something with solid mechanics that work together to make an interesting play experience, LA Noire is a failure. It is shallow, repetitive and unsatisfying. The trappings are there, an interesting setup, but I can not recommend this to people who wanted a well executed adventure game.