More then just a rehash?
The game features several upgrades from the original, including more general powers including the moab aka air fuel bomb times 3 and the emp bomb . It also extends on the general's features with new additions like emporer overlords and king raptors.
The units have upgrades toxin tractors achieving the painful anthrax gamma and the necluer upgrades for tanks.
The generals challenge really is chalanging on hard so u cant really complain its worth the money to grab it.