Mildly amusing: watching the "previously on Doctor Who" I could tell pretty much when I tuned out of the previous episode. At some point, I switched to scrolling through my phone while listening to the episode. It was really only the final scene with the electricity effects, which is decent considering how much I didn't like the last one.
Farting aside, the comedy is improved here. "I think you'll find the Prime Minister is an alien in disguise ... That's never gonna work, is it?" Elsewhere, the good to bad ratio is just a lot better than the first half. Jackie always adds some heart and Harriet Jones gets to do more than hide in closets and grimace about farts. She's a likeable character whose solid introduction sadly wasn't really capitalized on given future timeline changes. The Doctor's memory of her ("Elected for three successive terms. The architect of Britain's Golden Age.") is much better than what he ends up doing to her Prime Ministership.
We get some additional mentions of how young Rose is, which always kind of throws me. Billie Piper of 2005 is already into her second career and has been a public figure for seven years. Her music career started when she was just 15 and ended at 18, so even though she's already been retired for five years, she's still only 23. Still, she's not entirely believable as a 19-year-old, which is probably for the best given she ends up with a significantly older man.
The absolutely-no-budget alien explosion is very fun: the cutaway and throwing blobs of practical guts around feels like something out of Red Dwarf. It looks as obviously cheap as it is and that makes it timeless, because it looked like that from day 1. Contrast that with the CGI which must have looked a lot less pokey to viewers 20 years ago.