None.

Some monster violence, as some monsters are seen with wounds.

One monster eats a woman, and spit her clothes out. Not too graphic.

1 use of hell, damn and for god sakes

No worse than "damn" or "hell".

Some casual smoking.

There is a scene of a monster attacking an airport, whereupon he picks up a woman ("King Kong" style), and proceeds to eat her. Although the monster is seen chewing, there is no blood, and nothing graphic is shown, but the scene may frighten young children.

The monster's faces may frighten some.

The opening sequence is rather creepy.