These are soldiers based on the descriptions of the factions in the hypothetical real time strategy game that this particular contest utilizes.
These would be your basic infantry units that the game would use. Instead of drawing a particular unit, a zealot ala starcraft for example, I decided to focus mainly on the general visual styles and colors each faction might employ. Given that this is an RTS game i utilized fairly simple and bold colors for better player recognition and tracking. Each faction resembles the other via the common humanoid shape, since each faction is occupied by humans as opposed to inter-species galactic RTS titles like Dawn of War. They also employ camouflage textures, cloth/flexible materials and plate armor with an array of technological enhancements.
They differ in flow, configuration and philosophy (of what armor should do). Valiant has very thick, but relatively light, plate armor and advanced nano-tech fabrics designed to stand up to extreme heat, wind and general abuse that is endured on their homeworld. A fairly balanced approach to speed and strength.
Aquera, having to cope with an ice-age like environment, utilize a very insulated and self contained configuration to maximize climate, comfort, performance and flexibility. Favoring speed and agility over strenth. Biomoth, while also employing a similarly insulated and self contained configuration, has much more plate armor that increases endurance and strength at the cost of comfort, speed and stamina. Since their homeworld has a poisonous atmosphere Biomoth soldiers are equipped with extensive respiratory filtering and enhancement that adds weight to the already heavily equipped soldier. As a result strength wins out over speed.
I am generally happy with these concepts, though I wish I left more time to further develop each faction. Things like weapons and vehicles are extremely fun to do and I would love nothing more than to whip up a huge batch of ridiculous concepts ;D . I say there should be a "RTS challenge 2" right after this one! The idea is great.