Board Thread:Questions and Answers/@comment-92.233.39.118-20130307075338/@comment-7622429-20140623215936

The fact that they are have such a militaristic means they aren't just a big bunch of armed brutes. They have a dedicated military structure and specially crafted equipment, which means either the ones we'll be facing are a part of an exponentially larger overall military that have dug themselves into Mars, or a sizeable force of mercenaries accomplishing the same goals.

Regardless of which it is, these guys are like the Human armies of ancient times, but with access to space-faring-level tech and naturally enormous bodies. That coupled with Mars' lighter gravity and possibly favourable desert conditions makes them even tougher enemies. And from the looks of what little we've seen in battle, they seem to be quite smart in the field of battle as well.