Good "investigation games" that involve detective work are few and far between. One of the reasons is the amount of sheer structural effort creating these games requires. Unlike more action-oriented games, or even turn-based RPGs, investigation games don't have a standardized set of "gameplay systems" that have been iterated upon and perfected over a course of several decades.
The one exception
This has worked for Ace Attorney because those games aren't really "investigation games". Not any more, at least. Each game exists largely to provide a convenient narrative structure within which the player may enjoy the antics and interactions of the series' cast of characters with minimal effort.
In terms of player involvement, I would describe Ace Attorney in a single word: passive.
Every case in an Ace Attorney game is structured so that it lugs the player along, rather than letting the player think and forge a path through the mist of lies and deceit themselves.
The problem here is two-fold:
1. Ace Attorney stories are known for being incredibly bizarre. Given how familiar players are with the bizarre solutions the series employs, there is virtually no point to thinking very hard about the mystery at hand, because the truths behind each mystery are often completely and utterly nonsensical. Because of this, the games cannot possibly rely on the player's own wits to solve a case.
2. This has necessitated a structure where the player's involvement is minimal. In Ace Attorney, the player is simply required to present the right piece of evidence at the right time (sometimes by trial-and-error) in order to progress. The moment you do, the characters take over, sharing exposition and detailing the case with little to no further player input. There's also no real consequence to presenting the wrong piece of evidence, and you effectively get infinite attempts to do so. The "stakes" are entirely artificial.
In summary: an over-reliance on a standard set of systems has made Ace Attorney feel passive and repetitive. The player is not required to think, and even if they wished to, there would be little point to attempting to predict the series' bizarre twists and turns.
A Normal Lost Phone
From the moment it boots up, the game places the player at the centre of its mystery and tasks them with getting to work. The premise: you happen to find a lost smartphone. You don't know who it belongs to or why it's there, but it's up to you to piece the mystery together.
The catch: the phone's service plan is up and you can't use it to make calls or send messages.
A Normal Lost Phone's main menu approximates the look and interface of a smartphone. You have the standard Messaging app, E-mail app, and music player alongside others like a photo album, Weather, and Settings. (Which are cleverly the settings for the game itself but also play a role in the story)
Naturally, you begin with Messages. What better place to try and figure out who the owner of the phone is than to begin going through their message logs? And so, you get to work.
What you discover is that the owner of the phone regularly messages his friends and family, and that there's a whole lot of information to take in. Some friends know each other from school, some know each other from a board game club, some may or may not be acquaintances, and so on.
Given that there's so much information on hand, the player is forced to begin taking notes. Proper notes, consisting of names, associations, dates, and other tidbits of information that may or may not turn out to be useful. Think of the complex spiderweb-like evidence boards you see in detective movies, with the names of different people and events pinned up on a wall, and lines and arrows everywhere.
The reason this happens is because A Normal Lost Phone is structurally unfamiliar to the player. You don't instinctively know which pieces of information are relevant and which ones aren't, and so you jot them all down, just in case they come in handy later on. This is one of the advantages of investigation games not really having a standard set of mechanics or structure across the genre.
As you begin to make sense of the messages and explore the rest of this mysterious smartphone, you also start to figure out what your next course of action should be. The game actually makes this rather obvious, but ultimately it's up to the player to find the one relevant piece of information needed to progress, in a very large sea of info. A Normal Lost Phone is about going over the information, again and again, until you spot something that could point you in the right direction—like a detective.
It helps that the game is convincingly written. Every one of the contacts stored in the phone feels like a real person and you believe they could exist in somebody's life.
Eventually, you gain access to the owner's e-mails, where you find not just messages from friends but also reminders from services they've subscribed to, newsletters, spam, and everything else you'd expect to see in someone's inbox. These, too, are written with an attention to detail that mimics real life with pinpoint accuracy—including that fake-friendliness large social networking services or other similar "digital platforms" try to convey.
It's all so down-to-earth and lifelike that you honestly believe you have a real shot at finding out who this person is by putting the facts together.
On the subject of structure: A Normal Lost Phone does have one. Most of the game simply involves gaining access to different parts of the phone and connecting different pieces of information. It settles into this structure fairly early on, but because the game is not part of a familiar series and relatively short the structure never overstays its welcome or becomes predictable.
Additionally, because this structure does not involve any time limits or opponents you must challenge or health bars, there's no need for artificial stakes that serve no purpose. A Normal Lost Phone simply doesn't progress until you figure out what to do next, and in order to do that you constantly need to find your way around and put facts together without too much "help" from the game.
All these factors collude for an investigation game that's constantly unpredictable, refreshingly realistic, and—again—active. It's put me in the mood for something a little longer and more meaty.