In the year 1989, a simple window cleaner is working outside of a skyscraper. Intending to play a prank on his angry boss, the unlikely hero discovers a secret passage leading to a time machine along with mysterious alien documents. Operating the device transports the protagonist to the year 1304, where he is given a seemingly ordinary task of rescuing a lady in danger. However, he soon finds out about a much more serious threat of a global alien invasion. The hero has to travel to the remote future of the 44th century and eventually to the even more remote past of the Cretaceous period to foil their plans.

Future Wars is a graphic adventure game, and the first to use Delphine's proprietary Cinematique point-and-click interface. A right click brings up the verb menu. After choosing one of the six commands, the player points the mouse over the desired target and executes the action with a left click. Small objects are depicted by enlarged drawings once they have been discovered; however, many of them are well-hidden and often require precise positioning on the part of the player character to discover. The game has a linear story advancement, and it is possible to die or become irrevocably stuck by failing to locate a crucial item in one of the previous locations.