Call of Duty: United Offensive is an expansion pack for the original Call of Duty, enhancing the World War II gaming experience. This expansion introduces new campaigns featuring American, British, and Soviet soldiers in interconnected stories, allowing players to engage in significant historical battles such as the Battle of the Bulge and the invasion of Sicily. The gameplay is enriched with new weapons, vehicles, and multiplayer modes, ensuring a varied and engaging combat experience.

The expansion is noted for its larger, dynamic battlefields which encourage teamwork and strategic gameplay. Enhanced graphics and sound design contribute to a more immersive atmosphere, making United Offensive a notable addition to the franchise. Overall, it effectively builds on the strengths of the original game, offering players an exciting and deeper look into the European Theater of World War II.