What kind of phone are you using? The picture struck me as being a lot smaller than I expected. I don't know much about photography so I'm afraid I can't give you a proper critique. But on my phone (GS3) my HDR photos are more "realistic" looking your pic looks almost cartoony, but I believe a lot of HDR photos take on that kind of look. I believe the purpose of HDR is to allow for greater range between the darkest and lightest areas of a photo.
Anyways cool picture, maybe you could try taking more pictures with HDR of different scenes with different lighting and see what photo environments give you the best looking pictures with HDR.