I think the story is intriguing and the script is witty but, aside from a few decent performances, the acting is not too good. The mix between violence and comedy works well but tell me, please: How long could Vicki keep up her Cressida act? 2 years 1 year, 6 months, 2 months?
Fun Fact: The actor who plays Agamemnon, Francis de Wolff, was also the Vasor, the lechorous trapper in The Keys of Marinus.
I think it's acted really well throughout, personally, and it's one of my favourite lost story audios. As for how long she could keep up the act, I don't think it really matters. Doctor Who had a great way back then of tossing a character out and then forgetting they ever existed. I don't think we're meant to think on it too much.