For me The Host was a huge letdown.
The monster effects were not the ‘end-all’ special effects they were meant to be. Some of the plot points were so ridiculous I could barely stomach it. The main character was so stupid I didn’t sympathise with him at all. (The scene were his father defends him against insults, followed moments later by the son handing him an empty shotgun leading to his death – nice ).
The characters were like something out of a bad videogame (the sister who happens to be a world class archer with some confidence issues).
Add to that the usual ‘West are the bad guys’ side to it and you have a recipe for something absurd.

i don’t even think it was average, and i love monster movies.

terrible, terrible script and acting.

I’m sorry. I have to agree on the “prequel”. Not just for the above reasons (although I suppose the South Korean “Government” can cover it up by saying it is a deadly virus and the only survivors would be folks in yellow biohazard suits) but for another, like Travis and Grundy pointed out:

One of the big charms for me on the first film was the dark comedy and the dysfuctional, average “family” escaping/eluding the “Government” while trying to locate the missing young relative and fighting the creature. Yes, the monster was great, and well executed.

But now its all about the monster(s). Or so it would appear.
Hmmph.

Though the monster was great, the family dynamic was the best thing about The Host.