Took about 2-3 hours to beat.
The best thing about this game is that you not only have to track the gang member through several locations, but also have to collect clues to get the correct suspect. Beyond that, the size limitations of the time really detract from the game -- it only takes up a single 256kB floppy disk. There just aren't enough clues, possible suspects (several can be determined with gender, which is given to you at the beginning of each case, and one other clue), and locations to give this a high rating -- there are a total of 30 cities, each of which has its own file that takes up about 6kB. In a single playthrough (which takes 14 successful cases to complete), I had at least a half dozen repeated clues.
It doesn't seem to get any more difficult until you get the last promotion to Ace Detective where you have to follow the suspect to one or two more locations during the one week deadline that never changes throughout the entire game. They hadn't accounted for time zones in their time calculations, as well as how you wouldn't fly west from, say, Peking to Buenos Aires -- all flight routes seemingly have to stay on the displayed map (IIRC, a kid wrote to them pointing out how illogical this was). When you complete it and get entered into the Hall of Fame, I can't find where you can view the HoF in-game (you can open the hallfame.dat file in Notepad or some other simple word processor program, or even just via the TYPE command in MS-DOS), which would be useful since you can't reuse the name of any HoF members.
This was before they went heavily into the ridiculous items the gang would steal (such as the Statue of Liberty or Taj Mahal) as the vast majority of items stolen are believable. They also hadn't gone to the gang members having puns for names. So if those somewhat turned you off to later Carmen Sandiego games, this will be a plus for you.
The graphics are good for the time -- I've always liked the Keystone Cops bit. For being PC speaker only, the few instances of music and sound effects are good. They hadn't added mouse support at this time, but there aren't many controls, so only using a keyboard isn't an issue.
All in all, it's a decent early attempt, but I really can't recommend this version when they released several updates over the years that greatly expanded the game.
