I thought I read something about JJ Abrams wanting to create a large world, about the same alien invasion, but following different people's stories in different movies. John Goodman's character, I think, said something about the attack coming in waves. In the beginning of the first Cloverfield movie, you saw something being shot from the sky into the water. That was the first wave.

And I guess the whole race is biomechanical.

Personally I didn't really care for the movie. I mean it was well written, very well acted, and John Goodman was adequately terrifying like I knew he would be, but I just don't think it's a story I relate to or really care about at all (went and saw it because I was dragged along). The alien wrap-up at the end felt EXTREMELY rushed. Especially the part where that girl apparently throws a molotov cocktail like 50 feet straight into the air into the alien/ship's opening, and the whole thing explodes. From a molotov cocktail. Seems like a stretch.

I'm not going to say that they just used the Cloverfield name for marketing, but it does seem like it was a separately conceived idea that was later incorporated into the Cloverfield universe for a "what-if" sort of appeal. The movie lacked something all the way through, that gripping element that brings YOU into the story to relate with and care about the characters (they tried REALLY HARD with that breakup angle but then they didn't go anywhere with it), and the alien invasion story was meant to fill that void.

It didn't for me, it was much too forced, but I'm glad other people liked it.