Good game, but lacking long haul content.
One of the biggest problems is that you cannot allocate groups of units and usually end up selecting all the units as a whole. This causes problems with your units secondary abilities because there is no way to select which one you want to use. Meaning that you'll have your scorpions firing salvos, while your warthogs ram the same buildings. Most of the time you can safely throw strategy out the window and just get as many units together at once and flood the enemy winning on sheer numbers pretty much every time.
Halo wars is a decent RTS if you look at it purely from a console point of view. For those looking for an in-depth and highly strategic RTS you would be better off looking else where. This game is enjoyable while the campaign lasts and for a few games online, but lacks any real staying power.