Winter!: Prepare for holiday gaming!
When the original Generals came out, it was enjoyable, but repetitive to no end. The units were somewhat stale, and the variety in the missions was minimal.
Then along comes Zero Hour in a F-22 Raptor, bombing the dullness of the original into the stone age.
I believe that variety in tactics is what drives RTS titles in this day and age, and Zero Hour brought exactly that to what was a thematically dull game. The added units, superpowers, and themed generals allows anyone to find a play style that suits them, that they can use to dominate whoever opposes them on and off line.
Personally, I'm a China infantry or tanks general player most of the time, and I've never really tired of it. The graphics are exactly the same as the core title, so there's no significant upgrade there.
Overall, Zero Hour did to Generals what Halo 2 did to the Halo franchise: it brought a much needed expansion to the game mechanics along with some new toys to blow your enemy sky high with.
Game Traits applied to Command & Conquer: Generals -- Zero Hour (PC) by matrixrunner