Throughout the 20th century, an unprecedented political and economic crisis afflicted Earth, leading to the systematic disabling of it's programme to conquer outer space through lack of funding. The highest priority now was to carryout research into new energy sources, preservation of the enviro- ment and maintenance of the cultural heritage. However, at the dawn of the 21st century, provision of considerable funds from an unknown source released by the politicians of the new, unified government, permitted a return to the space research programme.

Throughout the 20th century, an unprecedented political and economic crisis afflicted Earth, leading to the systematic disabling of it's programme to conquer outer space through lack of funding. The highest priority now was to carryout research into new energy sources, preservation of the enviro- ment and maintenance of the cultural heritage. However, at the dawn of the 21st century, provision of considerable funds from an unknown source released by the politicians of the new, unified government, permitted a return to the space research programme.

The player plays the role of Tex Murphy, a down-and-out private investigator living in post-apocalyptic San Francisco. Tex is hired by a beautiful young woman named Sylvia Linsky to investigate the death of her father, Dr. Carl Linsky, a professor at the University of San Francisco. Prior to his death, Carl would not talk to his daughter about the secret project he was working on, and days later, he was seen falling off the Golden Gate Bridge. Sylvia suspects murder, but the police say it was routine suicide. To help get him started, Tex is given $10,000 and a few leads. The player is referred to the game's manual for a list of their leads.

Strider is set in a dystopian future in the year 2048, where a mysterious dictator known as the "Grandmaster" rules over the world. Hiryu, the youngest ever Super A Ranked member of an organization of high-tech ninja agents known as the "Striders", is alone tasked with the Grandmaster's assassination. Hiryu begins his mission by infiltrating the Grandmaster's capital at the Kazakh Soviet Socialist Republic. The game features multilingual voice clips during cutscenes (presented in English, Japanese, Mandarin and Russian).

Under a Killing Moon dramatically shifted the gameplay of its predecessors in the series by fully utilizing interactive 3D environments. The player controls the protagonist Tex from a first person perspective. The virtual world allows full freedom of movement, and as such allows the player to look for clues in every nook and cranny. It was also the first Tex Murphy game to stray from the traditional adventure game dialogue format of providing options that showed exactly what the player's character would say. Instead, descriptions of the dialogue choices were given, providing some mystery to what Tex would say.