The short campaign and limited storyline is compensated by the high-quality content.
The single-player campaign is cleverly scripted and suitably challenging, rewarding hard-working players with revealed tidbits which tie-in to key events throughout the main story. Joseph D. Kucan as his portrayal of Kane nearly carries the story through all by himself in the cut scenes, exuding the usual megalomania-loving maniacal insanity we have all come to expect from the Brotherhood of Nod leader.
However, players will be left wanting with an unfinished storyline regarding the previous game's events. In particular, GDI's recovery during the aftermath of the Third Tiberium War. And the Scrin themselves; as they prepare to launch a full-scale invasion force on a supposedly unsuspecting Earth. Scant little information is given, and will leave many fans disappointed because of the absence of any solid conclusion.
Overall, the small yet well-done campaign, along with the immense replayability offered by Global Conquest (especially with multi-player), will keep gamers satisfied for a long time. If only EA had included GDI and Scrin campaigns to tie in the rest of the storyline, this may have been one of the best C&C expansions ever released.