The game places players in the role of a child named Andy as he attempts to rescue his dog who has been kidnapped by shadow-like spectres.

[6] The game has about half an hour of storytelling cinematic sequences, thousands of 2D animated frames, and uses pre-rendered background scenery.

The player progresses through the game's linear storyline by navigating various environments and solving puzzles, all whilst attempting to keep Andy from being killed by evil shadows, hungry wildlife, and perilous obstacles.

Along with basic movement, such as running, jumping, and climbing, certain sections of the game give Andy additional abilities.

The game begins with the protagonist; a young boy known as Andy being abused by his teacher for sleeping in class where it is revealed that he has nyctophobia (fear of the dark).

Andy travels to another world called the Darkland in a homemade spaceship which promptly crashes and he has to face an assortment of obstacles to rescue Whisky and find his way home.

Throughout the game, Andy is tasked with fighting living shadow creatures and dark monsters while traversing several hostile alien environments such as a canyon, swamp, underwater cave, and lava river.

Another major antagonist is the Vicious Servant; a sniveling pink creature that serves the Master but is quick to betray him for personal benefit.

Andy ends up fending off droves of shadow creatures and successfully following through with his plan, but falls into the black hole himself along with the Master of Darkness as the structure around him collapses.

[11] An Atari Jaguar CD version was also announced in July 1994,[12] with internal documents from Virgin Interactive Entertainment stating that Amazing Studio showed interest in starting development on the conversion, but work on the port never moved forward beyond proposition.

"[20] After nine months of work without funding, the game was demoed at the September 1997 European Computer Trade Show, leading Interplay to adopt it.

[39][d] Jason D'Aprile said of the PC version, "It's not for everyone, and its age is beginning to show, but Heart of Darkness still offers superb animation, music, graphics, and atmosphere.