On the strength of the intriguing trailers and some reviews I'd skimmed, I took my two youngest boys (8 and 12) to a matinee yesterday.
My biggest initial concern was that the movie would be another bait-and-switch like The Bridge to Terabithia — billed as an action/fantasy adventure, but really something totally different. From the reviews I scanned, I gathered this was not the case.
I'm glad I took them. It is a fun movie, keying off of the thought that there is a world we can't see, which is surely true (2 Kings 6). The kids are believable enough, and come off as real individuals; the mom is neither perfect nor contemptible. The absent dad is contemptible — but he's supposed to be.
The special effects are as great as we've come to expect, and the sounds nicely heighten the tension. Some of what I read suggested that the movie might be too intense for younger children. I'm sure this is true of some younger children, but I'm not sure why this is such a theme in some reviews. My youngest is pretty sensitive, but nothing in the movie seemed to make him particularly tense, nor proved upsetting. There is some relatively mild bloodshed, some biting and scratching of the human children. If that in itself rules it out for you, now you're forewarned.
No sexual references whatever that I caught; some misuses of God's name, and a character says "Oh, s--" and is cut off.
I'm a bit under the weather, and not as sharp as usual — which, yes, I realize is a very relative statement, thank you very much for pointing that out, you're always so helpful. But I plan to discuss with my boys themes of the world of the unseen, Elisha's servant (2 Kings 6), the spiritual battle (Ephesians 6:10ff.), and divorce.
On that last note, and I suppose you could say this approaches a mild spoiler: the father has left the mother, and the kids. I worried as to how this would be treated; now that I've seen it, I'm fine with it. It isn't dwelt on at great length, except to show what a miserable situation it creates for the mother and children. The father's desertion is in no way shown as noble or respectable, but selfish, self-indulgent, and irresponsible. Nor is this depicted in a specifically male-bashing way; the mother is no plaster saint. But no child will come from that movie thinking, "Divorce is cool," or "Divorce is no big deal," or "Men are jerks." They may think "Men who leave their wives and kids are jerks" — but I'm really okay with that.
In sum: I recommend it. Worth seeing in theaters for the sound and effects, but it would make a fine rental as well.