I don't consider that a Cloverfield sequel. Everything but the last few minutes were shot like 2 years earlier but the studio never released it. Then JJ Abrams came along, added 10 or so minutes at the end and they put it out. I thought everything up until then was great, John Goodman was fantastic. Then it's like Michael Bay came along and added the final few min. The original ending had nothing to do with aliens or anything like that.

You might not have caught on to it: John goodman was really a psycho kidnapping killer of young women. He had his bunker where after he kidnapped them he would keep them telling her that the world above had some sort of cataclysm. For him, it was a possessive control over the women he wanted. He was insane. But unbeknownst to him or the girl the twist was there really was a cataclysm in which aliens invaded. If you got that then the movie was quite good.

Here's my theory on both the movies: [spoiler]They are both part of the same alien invasion story. The first movie documents the first wave of attack. In the footage there is a point where you see a streak of fire fall from the sky and into the ocean before the attack. I'm pretty sure that scene is actually at the end of the film. But, my theory is that the giant monster is the first wave of attack that the aliens used to cause havoc in big cities/population centers. The second movie starts off at the very beginning but being in a more rural area they didn't really know what was going on. They end up spending a lot of time in the bunker and at this point the aliens are sweeping the country side for people like exterminators. We find out that there is a resistance at the end of the film that is holding off the invasion. Now this leaves a multitude of options for a third film. I don't think that they would make a movie about the resistance because the movies are focused more on the suspense of not really knowing what's happening. So, any third movie will most likely be another aspect of the alien invasion. A perspective we haven't really seen yet. Could be based around how aliens would invade a desert location or maybe an island. Or I could be completely wrong and they aren't related at all.[/spoiler]

There's another one?

Cloverfield and 10 Cloverfield Lane aren't related. They are all just weird events related to a comic. The third one won't be much the same as the other two either. They aren't even the same director.

The monster in the first Cloverfield came from space though...