I liked the attempt at the origin story...

...of how the monsters invaded, but it doesn't make sense how they would be attacking even before the "meteorite" crashed... or am I missing something.

Also, it's shown that the monsters can't swim, so the people on the island think they're safe, but how did the monsters get there anyway? By chartering a boat?

And, if there's a third movie in this purported trilogy, is that how it's all going to end, with the girl's hearing aid ultrasonic screech being somehow transmitted on radios up and down the country as a weapon to kill the aliens or render them stunned so they can be shot?