I have to say, I agree with eleazar in that the Aliens feel very covert and "sneaky" in the first stages of the game. Now, this might be influenced by old feelings from UFO and XCOM, where the attacks began in a similar way.
The problem is that the story at the beginning does not match the beginning very well. Mumbai (and Bonn etc) are
huge events. It really makes no sense to start out so big and splashy for the aliens if they want to act sneakily afterwards. There is no recognizable "motive". Now, logically they're alien, and so are their thoughts, so they don't technically need a motive. But in storytelling, things should be causally justified or they run the risk of looking random. So, why after so many huge attacks in so much time, are they stopping and doing things slowly for months? The intro delivers a great sense of immediacy, of "now or never" feeling. This is of course great to capture the player right at the start, and it does. Problem is, it's not really delivering afterwards, as things move much more slowly once the actual game starts.
In addition, any reaction to something as big as Mumbai would be much bigger than the starting PHALANX.
I think it really is important to have a feeling to capture the player with right away, to draw people into the story immediately. And the Mumbai incident is greatly written as well, but it seems "thrown out there" on the intro. Maybe the game could start with more of a feeling of cold dread, you know, the "great unknown", things happening with no one knowing what's going on, feelings of powerlessness without overt hostile actions. You know, cows disappearing, local sheriff acting weird, and then maybe proof of some-
thing extraterrestial involved somehow. That would be reason enough to covertly recreate PHALANX and might be a good starting point for the game. Mumbai could be a new stage of the story, for example end of the first month or something like that, where the alien threat gets out into the public, and therefore all nations start financing and supplying soldiers, scientists etc. That would be a more natural flow of the story.
Hope it helps!