I love getting to see the TARDIS team relaxing on a holiday. A holiday which very quickly (from our perspective) goes wrong.

Ian and Barbara's domesticity is fun to watch, especially the joke about the fridge.

The Doctor's lyre-playing is a highlight of the episode. Truly cannot believe that William Hartnell was such a skilled musician

I actually think this is one of Hartnell's better stories, with the Doctor getting involved in the action. You can tell by this point that he's starting to transition into a more action-hero character, whereas in An Unearthly Child, Ian takes on this role, whilst the Doctor is portrayed as being a less active character.

Historical accuracy is fair for the time it was written, and the pacing holds up well today.