Dinosaurs! Brian! Riding a triceratops! Rory and his dad flying a spaceship! Rupert Graves in period costume fighting dinosaurs! Brian!

Okay, so it's never going to go down as one of the more deep and dark and meaningful episode, but, as you say, it wasn't meant to. It was a fun adventure, and as such it succeeded brilliantly. It's certainly one of my faves for this series so far (for 'favourite' read 'most rewatched').