Dark Earth takes place several centuries in the future, when a meteor collision with Earth tossed up great clouds of dust that blocked out the sun. Earth's remaining survivors began to seek refuge beneath small openings in the clouds, the few places light could be found. Those that remained in the 'dark earth' were hunted by strange creatures, infected with the darkness.
To shelter themselves from the dangerous 'dark earth', the people began to form cities beneath the light called 'Stallites'. At the time of the game, most of the citizens of the stallite have forgotten their history and now worship the light as a god. The stalites are run by 'Sun Priests', who maintain order and prevent the creatures of darkness from harming the city. The game follows the story of Arkhan, a "guardian of fire", protector of the stallite 'Sparta' and the Sun Priests.
After an attack on the sun priests, Arkhan has a poison thrown into his face that begins to infect him with the dark sickness. He begins to mutate into a creature of the dark and has to find a cure before his transformation is complete. Along the way, he is treated as an enemy by most of his former friends while he struggles to uncover the conspiracy behind the attack.
Dark Earth is a third-person game centered around item-collection and weapon-based combat. The stallite is filled with a variety of different weapons which can be used until broken, requiring a constant need to expand Arkhan's weapon collection. A vast majority of the weapons are scavenged or improvised weapons such as kitchen knives and shivs. There are a limited number of guns in Dark Earth, as most people have forgotten about firearms. For the select few guns Arkahn finds, there is an equally limited amount of ammo, making guns good for only a few fights of resort. Arkhan also must scavenge for food as it is his only means of healing.
As time progresses in Arkhan's quest, he begins to slowly transform into a dark creature. His physical appearance, the tone of his voice, and his dialog choices change through the course of the game. There is also a control for Arkhan to react to situations with his 'dark side' (i.e. he'll say rude things in dialog or treat his environment more aggressively while searching).
The environments of the game are all pre-rendered, with 3D modeled characters moving atop them (much like Resident Evil). This method, while allowing for much more detailed environments, prevents any camera control. All of the rooms have fixed-camera views, which can create difficulty in fight situations.
The game received praise for its graphics and story, but was criticized for its controls and difficulty.