The aliens present a welcome adversary to butt heads with, a useful purpose for much of your materiel in the form of guns, power suits, turrets, disposable combat bots, and all that jazz.
That being said, I've found the combat a low point in an otherwise outstanding and enjoyably complex game. There are countless ways to set up your supply lines and assembly complexes, but options for dealing with aliens are very limited. The evopollution mechanic is a neat concept and well executed, but the aliens are like rejects from a simplistic RTS game: One moves fast and is tough, the other moves more slowly and is somewhat weak but can attack at short distances, while the last is stationary, but very tough and can attack over long distances. None of these are dodge-able; if you're within range and they target you, their attacks will land.
Offense amounts to hit-and-run spamming of one or two sorts of disposable robots and by far the best personal weapon in the game, the combat shotgun with piercing ammo. The rocket launcher is shit, because you can only use it when well within range of worms' artillery and within the rest of the nest's aggro radius, leaving you ludicrously vulnerable given the slow firing animation. Defense amounts to shitting out lots of turrets, and perhaps getting a bit fancy with maze-walls, conveyors, and/or landmine blueprints... but in the end, especially later on, shitting out lots of turrets is all that really matters.
Furthermore, although my rails and power poles haven't been attacked yet, rails should be invulnerable. Having to build a meandering laser fortress wall of Trump around your fucking train tracks that span the map is totally ridiculous, and that's the only option that keeps the aliens out (other than metagaming their potential spawn locations, but that's cheating).
I hope they do a bit of work on combat with aliens and options thereof before release. I've noticed what looks like a flamethrower turret on their Twitter updates, so that's neat.
