three alien factions(Novus,Hierarchy,Masari) fight for control of our planet, with mechanics so different, you almost have to relearn the game when you switch between them:
The Novus, a race of artificially intelligent machines (whose creators were destroyed by the Hierarchy), use a network of energy beams powered by "Flow" to both expand their base and transport units; they also upgrade on the fly using "patches" to universally alter their defense and other capabilities. Resources are scavenged from inorganic materials and scrap from the battlefield via bots controlled from a recycling center
The Hierarchy, a locust-like race of... somethings... and the game's prime villains, employ gigantic upgradeable walkers as both weapon platforms and unit building structures; "hardpoints" on each walker can be outfitted with various options to boost production, offense and defense, both for themselves and surrounding units. Resources are literally ripped from the surrounding landscape by Reaper Drones, which will grab nearly anything: buildings, scrap, people, cows...
The Masari, a super-advanced human-like race (who, apparently, created the Hierarchy before being overthrown by them) manipulate energy to produce structures and units, as well as alter the way they fight by toggling between "Dark" and "Light" energy modes, each with advantages and disadvantages. Resources are produced by engines which collect it from their surroundings; in that respect, they have the least impact on their surroundings.
Each side also gets three hero units, with some interesting (but not game-tilting) special abilities. In skirmish games, they are unlocked by researching "suites" of related technologies; there are 12 for each race, but only six can be active at a time.
Every Faction in game is truly different that you have to use a different strategy for each faction.
The single-player campaign comes in four phases: the prelude (2 missions with the humans, which show the end of the initial invasion), the Novus (where we're introduced to Mirabel, the lone Novus "organic," and Viktor, her intelligent battle suit, through several missions), the Hierarchy (which centers around Orlok, the commander, and definitely showcases the Hierarchy's evilness), and finally the Masari (which has one scripted mission before launching into a grand strategic campaign ala Risk, Dark Crusade, etc).
All units are useful throughout the game and no one unit (except the walkers) is absolutely dominant.
I finished all campaigns and they are fun. The story is gripping. The graphics are not bad. some environment textures (like the Water textures) seem a bit low detailed.
Lets just say that It has a few problems:
1) camera is too close, I'd like to be able to zoom out farther than 40 feet above the ground.
2) Population limit; I'd like a wider range of units.
3) Pathfinding's not too good either, sometimes units go for a merry runabout of a building to cross a street, walkers - who can cross every obstacle, even rivers or steep cliffs - sometimes refuse to move.
4) the AL is also quite one of the worst I have seen in years. You need to control your units when performing attacks carefully. Units have no behavior controls. The base could get attacked and destroyed, and they would not react.
5) bugs; Game stutters badly in some situation, loading unknown data.
Overall it is a game that gives you an opportunity to enjoy a few fun hours in front of the computer screen.