I went because I heard good things about it from friends and since it was included in the London pass, I decided to give it a go.
The first part was a well thought out glimpse into the history of the bridge from Roman to Victorian times. Though the sets are a bit worse for wear, it was fun and the actors did their best to bring their characters to life. Especially the barman at the end was really engaging and I would have stayed and listened to him a bit longer.
Afterwards the scary part of the experience begins, within a haunted house style walking attraction. As there are several real people in there to frighten you, expect a number of jump scares. You walk through different classic horror themed areas which give off a bit of a ghost train vibe adding to the experience. Some scares are really unexpected and if you go there with younger children you might want to opt for their guardian angel option.
All in all a fun, scary experience.