Despite only having a Nod campaign, Kane's Wrath comes packed with a lot of high quality content.
Kane's Wrath spans twenty years of the Command & Conquer timeline. Beginning three to four years after the second Tiberium War, Kane still carries the wounds he received by McNeil's hands at the end of Tiberian Sun. With his successor Anton Slavik dead, and his own faction having branded him as a charlatan Kane must seek assistance in his return to power. With CABAL (the rogue Nod artificial intelligence from Tiberian Sun and Firestorm) nearly destroyed Kane has given him some modifications, and used his framework as the foundation for your character, LEGION. As Kane's new tactical AI you must assist him in his plans for over a scope of twenty years.
As is C&C tradition, the story of Kane's Wrath is told through FMVs between each of the campaign's thirteen missions. Joe Kucan reprises his role as everyone's favorite bald sociopath, Kane, and he shares the stage with two other actors I've never heard of but who never the less deliver adequate performances. The story isn't perfect, Brother Marcion the man who usurped leadership of the Black Hand from Slavik just disappears after a few missions despite all of the hype surrounding him. Also Act III which is set three years after Tiberium Wars is only a meager two missions of the thirteen mission campaign, with Act II which takes place alongside the TW campaigns receiving the bulk of the missions. This was disappointing to say the least, but I found the campaign to be a significant improvement over C&C 3's regardless because the mission design is more enjoyable.
Kane's Wrath brings some new additions to C&C 3. One of the most anticipated is Global Conquest mode where you can fight as one of the three C&C 3 factions against the other two over the Tiberium infested landscape of Earth. One nice thing about GC is that you can construct your bases anywhere, you're not restricted to certain nodes in certain territories. Bases are also mostly persistent, so you do not need to reconstruct your base from scratch every time it's attacked. Also the ability to create your own strike forces is nice, but it would have been better if you could just train individual units and group them together like in Star Wars: Empire at War, rather than waste time creating grouped forces in the strike force editor.
The other big feature is the sub-factions, which are somewhat similar to the sub-factions from Generals: Zero Hour. GDI, Nod, and the Scrin all receive two sub factions with their own strengths and weaknesses. I still prefer using the vanilla versions of each faction, but I found GDI's Steel Talons fairly amusing to play as since they rely heavily on the mech units from Tiberian Sun which were taken out of C&C 3 initially.
Video, and audio-wise there's not really anything new in KW. There's a remix of the classic C&C track "Act on Instinct" that occasionally plays during the score screen, and some new graphics and voices for the new units, and that's all above average of course.
Kane's Wrath is I'd say a must have for fans of C&C 3. It has a satisfactory story, a solid campaign, an amusing meta map mode, and the sub factions can be entertaining to play as. It would have been nice to have had a GDI campaign, but if they did that it would have likely been just six missions per faction instead of the thirteen we got with a Nod only campaign.