Jikuu Tantei DD: Maboroshi no Lorelei

The year is 2238, and the main character is a vampire detective. The game begins when a woman comes to his office and hired him for a job on board of the big zeppelin called the Lorelei. The game is a first person perspective 3d adventure game in which the player will have to use different objects and talk with all the characters to solve the mystery. The story is set in 2238, but the main character, Detective Narukami, travels back in time to 1939. He's headed for the Hindenburg in search of a client's father, but instead discovers conspiracy and mystery. The voice acting (done by a professional radio announcer, I guess) is excellent. The game features characters voices, a lot of movie sequences and detailed graphics.