I also enjoyed this episode. It seems that Capaldi works best when he's given 'classic' style stories. There's the monsters, the danger, can't use the Tardis, important-type-talking but all with the hint of that dark side to The Doctor. "You were an excellent Doctor, goodness had nothing to do with it" - sums up the tough (impossible) choices he has to make all the time.
So, I'd like more of this, action adventure mixed with a balance of the silly and the dark, I suppose that is a lot like Tom Baker era stories, and that's ok. Less of this "big important mystery that I'm shoving in your face and then blatantly not resolving for ages" stuff Moffat.