Murder! can be quite compelling, as there is a wide scope for detailed questioning. You can also take fingerprints from possible murder weapons, and try to figure out what the weapon was. In fact, you need this to win the game, because to win, you need the murder weapon in your possession, plus you must accuse someone who you think might have committed the crime.
If you're a fan of spy novels, the game may indeed be worth your while because harder levels can be very interesting. For instance, characters might lie about themselves, or be involved in supposedly "secret" love affairs with other characters. For all of the game's attention to detail, however, sometimes the levels can be solved within 30 seconds by sheer luck: just find the nearest weapon to the scene, speak to the nearest person to find out who had a motive to kill the deceased, and accuse them - very often this turns out to be correct! Of course, this really isn't the correct way to play the game, and die-hard sleuths will cry "foul!" But the fact that you can "cheat" in this way reflects a poor design. Overall, if you enjoy spending a lot of time questioning suspects, trailing people etc., and can tolerate a cumbersome interface, then you will probably enjoy this game.