Not a perfect attraction, by any stretch of the imagination. But (and I say this without wanting to spoil too much - most of the fun is in the surprises) elements of Sub-Terra represent some real balls from Merlin. There's a commitment to storytelling here, and to crafting a full experience, that should be applauded and encouraged. Go in wanting something that'll make you puke, and you'll come away disappointed. But be hungry for something different, something that embraces what theme parks at their best and most unique can achieve, and there's much to value here.