The nightmare.zip file you have requested: Maps Levels Missions / Multiplayer / 6 Player / Nightmare - 762.2kb is not available. Perhaps try browsing all files for the game C&C3: Tiberium Wars and upload any files you want to share or are missing. This is the only information we could locate:
A six player Command and Conquer 3 map from Woodbulb. It's a fun mix of desert, city, and grassland.