Deadlight is a 2.5D side-scrolling survival horror platformer set in 1980s Seattle. Randall Wayne, the protagonist, murders Karla Patterson in the warehouse. She was Stella’s sister and one of the few survivors who hid in the building to avoid the Shadows, the zombie-like undead who pursued them. Karla had been bitten and became infected. Sam Powell, Benjamin F. Parker, and Stella Patterson are the other survivors in the complex. A ladder breaks down as they seek to flee to safety, and Randall remains behind. He meets the Shadows alone but tries to reach a safe location where he can find his family. Only 145 days before, the first sufferer began spreading the virus that devastated society.
Randall is moved linearly across a horizontal 2D plane while the world is in 3D. He can run, kick down doors, operate equipment, and jump and grab ledges to ascend on platforms. The game prioritizes escape devices and riddles above combat and confrontations. Large portions of the game are devoted to defending against the undead by employing backdrop items such as shifting a cabinet to block a door or crushing the zombies. He can look at numerous articles of interest and journal pages saved in a separate part called Randall’s Memories. Other times, they have Randall perform environmental observations to catch the Shadows. When he is close, items that can be interacted with are highlighted by blue gears. Combat is often optional and discouraged, but fighting with a flaming axe and a gun is possible. Fighting fast depletes a blue stamina meter, and the screen pulsates in blue colors when low. Running also consumes it. When Randall spends too much time fighting, more Shadows emerge and overwhelm him. Once the undead have been defeated, they can be eliminated. Initially, three health points are healed with first aid supplies.
The game employs a graphical style in which the backdrop does not always fill the entire screen. When a site is reached, it frequently fades in and out, and larger areas scroll along regularly. The camera zooms in on small areas. Cut scenes are drawn in the style of a comic book.
