I like the abstract reference to water in #11 and overall I like the circular form. #12 is a little too minimal, but I like that more of the horse silhouette is visible. The trees in #11 could go away and just leave the water reference. More color might help make it more fun and interesting.
I only moved your other ones to the 'non-interesting'' box because I like this one much better. This comment is quite finicky, but the horses mane looks a little on the "unfriendly" side - a smoother more flowing mane might appear softer.