Covert Operations is an add-on for Command & Conquer which features 15 new missions, new music tracks, and multiplayer maps. Unlike the original game, the missions of Covert Operations can be played at any time and in any order, and are not accompanied by mission briefing cut-scenes. It added two new units to the game, and the new missions are more difficult than those of the original. The add-on pack features the DOS version's soundtrack, which includes music that was absent from the Windows 95 (or Gold Edition) version. Covert Operations was originally needed to unlock secret missions, which were later enabled by a patch to the main game.