Besides the well-done terrain, the characters in the game are also done extremely well. One of the things that really makes Myth special is all the extra touches. Debris is also left on the battlefield, which makes things much more realistic. I never understood why in other games if somebody died they magically vanished after a few seconds. With Myth when the end of a battle arrives you're left with a blood bath.
Dead soldiers litter the scene, if they die at the beginning they stay there till the end.
One other thing that separates Myth from the competition is that there is absolutely no resource management. You don't have to harvest ore or collect energy or even build a base, you start out with an army which allows you to focus all your energy on combat. There's no need to piddle around with anything else, you can cut right to the heart of the matter so to speak. You might think that this limits the strategical element of the game but in fact it does the opposite. Since you only have a limited number of troops you have to take care of them.