I agree with the above review that it's a nice trend for the animators to have a little free reign to expand upon and hopefully flesh out the manga. However, this episode looked bad in my opinion. Even side characters like Sakura, didn't look right. Pain's face kept contorting into bizarre facial expressions. Also, it was ridiculous to see Pain get beaten over the head with a giant rock. Nobody, not even Pain could survive that.
When I read this chapter in the Manga, I thought the 6/8 tails Naruto looked strange but I had high hopes to see this animated, but felt let down.
The water looked cool, but Pain doesn't have that power and the animators completely disregarding the surrounding landscape to fit it in. Also what was with those weird giant roots?
I just wasn't pleased with this new style.