I actually enjoyed it even though it shares the same theme as just about every recent big money sci-fi thriller; evil US government/military vs misunderstood alien. It was exciting and suspenseful and the child actors were surprisingly good IMO. Bogged down in a few spots with teenage angst but overall it was a very fun film and I would recommend it to anybody that liked any of the early Spielberg films, I have read that is very similar to E.T. and The Goonies, but I never saw those so I can't make the comparison. I had fun and my son and his friend enjoyed it as well.
* edited to add that if you do see it stick around for the credits, there's a very funny scene hidden in there.