Meh.
My thoughts on the Alien Invasion genere is that it has yet to be done right, and I don't get a paticularly fantastic vibe from this or "Skyline".
See, the problem I have with movies like this is that they all seem to share the same flawed assumptions.
In general most of these movies seem to assume that any alien species capable of space travel is going to be far more advanced than we are in every other conceivable way. That's not true, because scientific development doesn't follow a straight A to B path. Typically it starts out with imagination, someone deciding they want to experiment with something or develop something specific, and discoveries are made along that road. Take for example the classic "laser gun", there are far more efficient ways of blowing holes in things, but for some reason we've been enchanted with the idea since we first thought of it. Every year the lasers get smaller, more portable, and more powerful. In chasing this impractical technology we've found all kinds of things we can do with laser technology that we wouldn't have otherwise thought of. Holograms, communications, surgery, and all kinds of other things that can be achieved by playing with focused beams of light. A species that thought (and quite logically) that making a laser gun was stupid and inefficient would probably have missed this entire area of science and a lot of those developments. By the same token, something like space travel could be uncovered as an unexpected result of an area of science we thought was impractical for similar reasons.
One also has to consider that if they are going to bother to invade, there must be something that they want on earth (even if it's the planet itself), and some reason why they wouldn't otherwise at least make other attempts in dealing with us first. All comments about the bad things that happen when a less advanced civilization meets a far more advanced one, tend to also overlook that in most cases in our experiences here on Earth there have been other factors involved. For example things didn't get all that bad with the native Americans down here on The East Coast, until the majority of tribes decided to (very knowingly) enter into an alliance with France against the British, and then wound up seeing France lose the resulting conflict. People underestimate what a huge turning point that was, and tend to hear things from the perspective of "evil white men" coming in and killing and pwning everyone as soon as we were here in strength.
At any rate, the point I'm getting at here is that assuming we get to the point of an "invasion", even a surprise attack, I don't think that things would be quite as one sided as most of these movies entail. For one while we haven't used our space technology efficiently for political reasons, humanity is itself in capable of a lot more on that front than we use (we could be colonizing Mars). While it was cool when aliens were a "new" concept to have them stomp all over humanity in "War Of The Worlds" and such, realistically I do not think that anything is going to be laughing off missles capable of wrecking buildings or shattering mountains. I mean when you consider the fact that we have the firepower to literally destroy our own planet a hundred times over, I have a hard time seeing some tank/walker or low-altitude gunship taking a lot of these hits. Especially when their own guns don't seem to be all that much more effective than a missle (sure, it blows up a building with one shot, but we can do that too).
I guess what I'm getting down to is that doing it right would be more of a war movie than even this appears to be. I mean it was cool and all to show off all the fancy FX of having explosions and firestorms around alien war machines, but it god old. Plus, typically we're not exactly dealing with situations where the science is as advanced as say Settlers Vs. Indians proportionatly. Where an Indian had no idea of a gun, a boat, and similar things, just about anything we see in these movies we have a frame of referance for. Plus we know (on average) a lot more about physics and what things can actually do.
I think it's kind of darkly amusing when I occasionally see a movie where some alien sits there and has bullets bounce off it's "super armor" and then pulls out a "super gun" and blows a chunk the size of a basketball out of a wall or something... and then it occurs to me that a lot of the weapons we have now would actually do better.
I'm rambling but I guess it comes down to the whole "Snipers Vs. Fantasy" arguement. Going back decades we've had guns (like the one in the old "Navy Seals" movie that the sniper had, I can't remember the name but it became an RPG staple for a while after that movie) that can literally shoot through concrete walls from nearly a mile away to kill people. Whether it's a monster, or an alien, a wizard, or whatever else, very few things most people think of could deal with someone simply sitting there waiting for it with a scope. The whole "The Last Thing You Never See" bit. Then of course there is the entire issue of field artillery which is typically also forgotten. Generally speaking the best weapon of the infantry is not their rifles but the abillity to accuratly tell the guys that could be dozens of miles away with ginormous guns and missle launchers "shoot here".
I guess the point is that the definitive "invasion" movie is going to have to deal with these kinds of things IMO. What's more anyone who resorts blindly to the "any sufficiently avanced technology is indistinguishable from magic" thing is just writing badly, because that statement was made when talking about differances so extreme that one side totally lacks a frame of referance... which is not the case, we know what a "space fighter" is, and can understand the concept of a "gun", and similar things. We even understand a lot of things that we can't quite make ourselves yet.
As soon as we see the tanks rolling up a hill towards a killer space walker (like in the recent Tom Cruise "War Of The Worlds" remake) we can assume whoever made the movie is an idiot who is putting spectacle above common sense. Modern tanks are designed to move fast and shoot from a REALLY long distance away. Given the limited engagement range of the enemy's weapons in that movie the guys shooting them would be doing it from like miles away instead of figuring "oh gee, let's roll the tanks right up into their range because it looks dramatic...".
