Famicom Detective Club 2 is a "visual novel" that owes quite a few debts in its overall style and presentation to Snatcher and Clock Tower, though it doesn't have nearly the gameplay that those two games do (and yes, I'm aware the first Famicom Detective Club predates both those games, I refer more to the aesthetics of the game, particularly the music - don't even try to tell me they didn't totally rip off Scissorman's chase theme).

To make a more recent comparison it is somewhat like Phoenix Wright, but with most of the gameplay excised - think of the portions of Phoenix between cases where you are gathering evidence without the courtroom scenes, or Snatcher with just the investigation portions and without the gun battles, and you pretty much have this game. As long as you grind your way through every available menu choice, you'll inevitably progress the story as there's no way to make a wrong choice or die. In fact, you could actually set a monkey in front of this game, and provided he didn't break the equipment he would eventually work his way through it. Good job, monkey! You're a real detective now!
That's not to say the game doesn't have its qualities, of course. Developed by Yoshio Sakamoto, the "other guy" at Nintendo who has been responsible for all the Metroid games since Super Metroid as well as the Wario Land and Wario Ware series, it's an extremely polished game with excellent art and animation. Additionally, much of the team responsible for Super Metroid worked on this one, including composer Kenji Yamamoto who brings some pretty sweet tunes to the table here (even if he did totally bite off Scissorman, at least it sounds cool).
The game bears a release date of 1998, which is interesting as the Super Famicom was pretty well dead and buried at that point. Apparently Nintendo Power's Japanese arm distributed blank cartridges which could be brought into the Japanese equivalent of Gamestop or whatever, and you could pay to download games onto them; Famicom Detective Club 2 was one such release. I don't know too much about the details, but I'm guessing the cartridge scheme was rolled out while the Super Fami was still in its heyday, and thus with the minimal distribution costs from having the system in place Nintendo of Japan was still able to see a profit in releasing this one nearly two years after the console had been packed off to the retirement home. Kinda interesting stuff. Anyway, on to the story.
 You play as some 15 year old kid who never knew his real parents, and has run away from his foster home to the big ... well at least medium-sized city. One night the cops chase him for no good reason in typical cop style, and just as they are about to haul him down to the station just for being outside at night (typical pigs), this smooth talking pederast shows up and convinces the pork to leave.
Young man! There's a place you can go!
Over coffee, a beautiful predatory relationship develops as the guy makes like it's a gay porno and opens up his ... home to the confused young supple runaway boy (I was actually worried this was going to be one of those "yaoi" hentai games the first time I played this). As it happens, he's a private dick (go figure!) and rather than getting the boy into a local school he begins "training him as his apprentice". So not only does he have live-in underage ass, he's also got an undereducated slave to do all his work for him ... such a deal.
 So in this game you'll play as the boy, who investigates the mystery of the "Girl In Back" ... actually a more literal translation from the original would be "The Girl In The Rear", but I guess Tomato and Demiforce felt the game was laden with enough innuendo already. So, some schoolgirl washed up on a nearby riverbank all strangled and stuff, and you go to her school to uncover who the murderous perpetrator was and all that.
The game does a pretty good job maintaining suspense and functioning as a thrill/horror ride, in spite of the fact that you can't ever die and it never really gets particularly gory. The only real problem with it is that there's virtually no reason to replay it as it's exactly the same every time, and if you don't like text-heavy games there's going to be no reason for you to even play it the first time as it's all about reading. They don't call 'em "visual novels" for nothing, y'know.

Anyway, the only thing that is variable is that at the end you get some weird personality assessment and a "love rating" for the main girl of the game, which affects a small cutscene at the very end. I think those two things are determined by what order you choose menu options in and how often you choose certain things, as well as a few questions you are asked here and there throughout the game.
So, don't expect deep gameplay or anything, but if you want to watch a decent little detective story unfold and don't mind a little repetitive clicking, this game isn't bad. It's probably worth a peep just for the music and art alone. If you were paying for this game I would say it isn't worth the money (it is available on the Virtual Console in Japan, I do believe) as it almost completely lacks any actual gameplay, but since people in the English speaking world are likely only going to be able to play this through a ROM download and an emulator, the only investment is 4 to 5 hours of your time to see the story all the way through to the end.
 Links :
Demiforce/Tomato translation @ romhacking.net
 Videos :
Gameplay Video