[Ratoslov]

Part of the problem of making a game about investigation is that investigation inherantly involves a lot of drudgery. It's all about correlating pieces of diseperate information and seeing what comes out. So here's an idea to make things interesting:

You get a number of people you can pick up as assistants on a case, who you can assign to do work, or you can do the work yourself. (Work, in this case, means interviewing people to get clues out of them or examining piles of records to find the interesting part (i.e., puzzle games)) The investigation is timed such that it's impossible to finish it without handing off at least some of your work to the assistants. However, your assistants are unreliable and have biases, and therefore you need to decide which ones get which assignments. It may become necessary to go back and interview people who your assistants screwed up. (A late game case would have one of your own assistants be the criminal, and the only way to solve the case is to examine information that's marginally incriminating, copy it, and assign them to check it out.)