How odd, I thought it was much less Gaiman-y than I expected, but in a good way. I love quite a few of this works (Sandman, American Gods, his short stories) but I was afraid that he'd make it too much his own thing, and not proper Who, and instead he gave us the episode in Eleven-era that I find truest to the spirit of the show.

But you're right, now that I'm thinking it through, it had certain Gaiman trademarks - a bit of horror/gothic, a rather dark aesthetic, a hopeful ending, a personification of a usually non-human entity, figures with names like House/Aunt/Uncle/Nephew... okay, yes, it was very Gaiman.