There's just too much going on here. Trying to cram the Doctor and Donna's reunion, the Star Beast story, Rose's introduction, and undoing Donna's amnesia all into one story made it so that none of those elements was developed enough.

The dialogue runs the gamut from fantastic to terrible. Funnily enough, I think both of those extremes were in lines referencing gender and transness: "My preferred pronoun is the definite article" and the "male-presenting Time Lord" bit, respectively.

Most importantly, BBC Worldwide are imbeciles for not having Meep plushies in every store for Christmas. How did they miss that opportunity? They'd have flown off the shelves! (Yes, this is about me wanting a Meep plushie.)