You are a reporter, who has just been assigned to New Orleans to try to crack a heroin smuggling ring known to be operating along the waterfront. Arriving with $500, your goal is to befriend the strange denizens of nighttime New Orleans, and try to solve the case. Night Walker is an adventure game where you explore a map of the New Orleans waterfront, visiting different locations to gather clues. When the player enters a building, they go into text mode, where they can answer yes/no questions to advance the story. They can also make observations, which can be used to query other characters at a later date. There is also an inventory system, and the player can bribe characters from their limited funds. The player can enter all buildings only once, and must gather clues during this encounter. If they miss important clues, they can not reenter a building, making it essential to visit buildings in the correct order. The TRS-80 version has a 2-dimensional map represent the New Orleans waterfront, while the Commodore 64 uses a 3-dimensional display. Otherwise there are no differences between gameplay or story.