These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fans Prefer the New Her: Liz looks rather better as a blonde - since actress Thora Birch is naturally blonde. The black colour doesn't really suit her and makes her face look quite gaunt.
Fridge Brilliance: Rather a lot of it concerning Liz's version of events. Notice how the whole story focuses on her attraction to Mike - and them being locked in the bunker takes a back seat to Mike developing feelings for her. It's basically an in-universe Romantic Plot Tumour for Liz - telling the psychologist all about the way her and Mike "fell in love".
Even more. In Liz's version, Martyn locked them in to make Liz realise that Mike is not so great and that she should love him instead. Liz makes the entire thing a story of two men fighting over her. She's trying to make herself look like some tragic heroine.
Magnificent Bitch: Liz. At the end of the movie she has pinned her own messes on the deceased Martyn (whom she killed) and the police psychologist, leaving her free to go and in an Alternate Ending find another boy to obsess over, this time calling herself 'Beth' and having dyed her now-long hair blonde.
Retroactive Recognition: Keira Knightley, who had only done Princess of Thieves and the first Star Wars prequel prior to this. She's easily the most recognisable star in it today.
Laurence Fox (Geoff) would be more recognised from his role in the cop drama Lewis.