Byzantine: The Betrayal is a first-person adventure game in which the player takes the role of an American journalist, summoned to the city of Istanbul by an old college friend with the promise of a once in a lifetime story. By the time the player arrives police are already on the scene, his old friend, Emre, has run away. Players must use their investigative skills in order to uncover the secret he struggled, but failed, to reveal. Failure could mean death.

The game plays in a typical first-person adventure fashion, providing 360º of freedom of movement around the player, as well as the ability to look up and down. Locations are presented as static images and talking is handled similar to that in the Tex Murphy series, with live cast and photo realistic surroundings. The game incorporates details of Turkey's history, as well as that of Southeastern Europe and so the player will have to make use of an abnormal piece of technology to investigate through the past and save yourself in the present, uncovering the secrets that lie behind Emre's disappearance.