From what I can gather, 'Caffeine' is the British attempt at a diner movie. Diner movies are your typical workplace comedy taking place at a diner. One famous example is 'Waiting' starring Deadpool- I mean, Ryan Reynolds. The problem with this British version is that diners are so classically American that we don't want to see a movie about British people working in a diner. That's especially true when you can't even tell whose accent is real and whose is fake.
Katherine Heigl and Mena Suvari are in this movie, along with a host of British actors. Katherine Heigl puts on a British accent, which makes me wonder... is this how British people feel when they watch one of their actors do a bad American accent? Why don't we all just make a pact and just use our real accents from now on.