I loved it and think is definitey a spiritual successor.
You'll notice I've said lots of good things about the game on this forum, but I do have one gripe. One small gripe.
One thing I loved about BK were the little extras (ice key, tiny island coming soon etc). The secrets that are found by exploration and curiosity. They did include this in the game, but I wanted more.
Everything else was pretty self-explanatory or literally explained to you.
So yeah. That's my small tiny gripe, but I also don't think it takes away from the game. Still a great game. Still a success.