There aren't too many unique features. It's just a real time strategy game. You produce workers and have them harvest resources to build units so that your war can continue. The main draw is probably the focus on hero units though. A number of units in the game have special abilities. For example, the cyclops unit can pick up enemy soldiers and throw them far away from the battle. The centaur character has a sniper shot that instantly kills weaker units. The sheer variety of abilities and special powers makes each fight quite cinematic and interesting. It's certainly better than a battle of health bars.
The other big feature is the overall polish of the game. For an older title, a lot of effort is taken to make the little details right. If a cyclops throws an armored soldier into a forest, the trees are realistically knocked down in its path. Similar effects work for the special abilities too. It's a minor aspect, but it makes the battles a lot more interesting to watch.
There is a good amount of variety in the units too. Standard soldiers are mixed with relevant mythological units for each of the three story sets. You will also have a number of hero characters to give a little more strength to your army.