Sound is equally good with nice sound effects for combat and ambient sounds (although some of the cities seem to have an awful lot of loud angry cats running around) as well as the same half rock, half symphonic score playing in the background of your battles. Superweapons continue to impress and the new heat wave effect for the US microwave tanks is a pretty good one, even if it can make things a bit confusing on the battlefield occasionally when you have a few of them in your army. From a graphics and sound stand point, Zero Hour remains true to Generals with slick visuals in terms of texture, lighting, and effects. Regardless of this, Zero Hour is a damn fun game that adds a lot of gameplay and hours even if there aren't really 30 totally unique new units in the game. It's like saying the blue zombie and the red zombie in Diablo II were really different creatures.
Yes, technically they're a bit different, but the ad campaign has been a bit misleading on that account. There are new units on each side and some modified versions of other units that can be used when playing as one of the specialized Generals such as the Emperor Tank, that's basically a more powerful version of the Overlord. First off, you've been seeing this whole 30 new units campaign going on, and really, that's some marketing BS.