S.T.A.L.K.E.R - Winter of Death ULTIMATUM is a mod for the Call of Pripyat STALKER series. It is an action-themed, first-person shooting game with graphics and animation elements similar to those of Counter-Strike. This mod features a winter-themed environment with highly textured and detailed landscape design. The game still supports the other types of seasons, and players are free to shift from one weather setup to another. As a predecessor to the Winter of Death mod, S.T.A.L.K.E.R - Winter of Death ULTIMATUM maintains the same mechanics and gameplay while sporting a different narrative storyline. Players are tasked to embark and accomplish fifty different quests that are strategically categorized under serial missions.
S.T.A.L.K.E.R - Winter of Death ULTIMATUM comes with a new introductory video clip that presents the protagonists, as well as the main storyline of the game. Weaponry and ammunitions have been added to. Gaming vehicles have also been modified to fit specific quests. Additionally, new food supplies, first aid kit apparatus, and other necessities have been incorporated to give it a realistic touch. Minor changes on the game's resolution made it easier to adjust the display size to fit various monitor screens without compromising pixel density and intricate details.