2D horror 10-103: NULL KELVIN tells the story of a lone operative sent on a deadly investigation. The main character finds himself in a research center, where he will encounter mutated and angry animals. The base received reports of violations of containment conditions and safety regulations. A single special forces soldier was sent to find out what was going on.

The perspective is presented with a side view, and the graphics are in a pixel style. The player will have to investigate a violation of the UT class containment conditions with a danger of 4+ points out of 5. Communication with the previous team and the center employees has been lost. There is only one soldier left at the base, who the user will need to control. The cameraman guides and assists the central character. He uses the radio to indicate possible locations of enemies and control points to explore.

Gameplay lasts about 10-15 minutes of real time. The horror atmosphere increases with each room passed. There is more blood, the sounds are more terrible, and the opponents are larger and more aggressive. The operative will encounter mysterious creatures and will resist by using firearms, running away, or interacting with the environment. The user can use the radio to receive new instructions or report a discovered and important item.