The Blackout

I am tired of finding faults in this movie, there are so many of them. Please do not let these scriptwriters write any more scripts. 2 stars for good VFX.[spoiler]Why did this alien, who waited for 200000 years to give just 3 orders, bungle 1 of them? Why was this advance craft not capable of emitting the 2nd wave more than once? If Ra had the weapons of the rest of the world at his disposal, why did he send foot soldiers to group and attack? He could have just made them throw bombs and missiles and blow 'The Circle of Life' to kingdom come. I mean, he did blow up the outpost towards the end, so why not the rest of it? Why did Ra even stay on the building when he knew Sasha had seen him there? He could have just walked to another building. Why were all of the zombies/freaks/radio-controlled humanoids/whatever just attacking the building from one direction? There were lots of other roads leading to the building, as is evident from the overhead shots. In the spaceship at the end, why didn't they just shoot the main pipes - you know, the fat ones?[/spoiler]