It is most certainly NOT good. Its so bad that stores were giving it away for free with any purchase of a 3DS. I got it for free, played it once, now its just sitting on my desk. I don't even count it as part of my collection.
Nintendo really should have made it a fun game. They didn't add any of that Nintendo charm that makes their games good. They could have made a really fun game with submarines, but just went with the really repetitive and bland route.