Nightlong: Union City Conspiracy takes the player to Union City, where he will play the role of investigator Joshua Reeve. The action takes place in 2099 in a futuristic place. The gameplay combines adventure with point-and-click controls. You will also need to find hidden objects and solve puzzles. It all starts with a call from Hugh Martens, a longtime friend who is currently the city manager.

The main character receives an important political task. Soon the city may be attacked by dangerous terrorists. Also missing is the mayor's friend Simon Ruby, a reporter who previously investigated dangerous criminals. Now Joshua takes charge of a criminal case to learn about all the secrets and possible threats awaiting the city. Much of the gameplay is focused on finding items and exploring the environment.

Many things are necessary in the next stages of the passage, which is why they simply lie in the inventory. There are several actions available on the interface. Navigation helps to find out detailed information about an object or object on the territory. The gamer can combine things with each other, use or study an item in the inventory. When the ward interacts with the environment, the character tells stories, his thoughts and conducts other monologues.