Immediately the use of 6 and 7's umbrellas tells you exactly what this story is going to be, just some fun references and great characterisation.

I love 12 using the username JohnSmith12, I love the blathereen being there because of course why not, I love that Iris is betting on the TARDIS to get spare parts, I love 'Planet Wet', I love that they use Rels for time measurement because this type of megabuisness is inherently evil

All in all, just a fun story to end on, and just fun is just right for this.