Is there multiplayer in this game? If so, how many players can play? Also, is this like starcraft where you build a base and attack someone elses while defending your own, or is it that you can't build a base, you just lead a group of people around.

Answer: No their is not a multiplayer mode, also it is not like StarCraft, and yes you do lead a group of people around but their's more to it than that.

yes theres an intertwining storyline whilst you play, example:

has an alien "god" so to speak has you control your hive. Your going to have to spend "food" points to coat the walls with a sticky resin so your aliens can regenerate and so face huggers can survive outside of the egg. Your going to have to set up patrols(you can command them to do it without you haveing to guide them through every step) your going to have to set up a route so youll have your aliens getting hosts while your tending to the egg chambers. Your going to have to command your other aliens to drag the eggs away so the queen has room to make more. Your going to use your warriors and drones to protect the outer layer so your prepared if your scout "reports" a leathal disturbance. Your going to ahve to balance your "fod" points so you can expand the hive and to have a few praetorians hidden and sometimes protected incase a fatal force invades the hive and kills the queen. And after this process produces a large hive(at the very least 25+) then you can get mobile to do the tasks set for you(do all the side tasks to unlock cheat mode) While your mobile clear an area and leave a praetorian there with a guard or two in case of a serious fatality. Now while this will weaken your fighting force it will leave you soemthing to fall back on
rather then just meet i group of huamns with rocket launchers and a flamethrower and say goodbye to a half hour or more work,

i believe thats a sufficent sumamry, no?