The Brighton Penny Arcade Museum is a museum because it displays antique machine and gives some description about them. That is where the similarities end. Most of the machines are working, and so it is actually a chance to play some very old games using the old British pennies (which you get by purchasing them at the main counter). There are a few that can be used by directly inserting 20p. The descriptions of the machines are not lengthy and there is little information telling you about how popular they were in the past, what age/class/gender would have used them at the time, and what public opinion was of them at the time. There is a small sign tucked away that explains how much other items cost in the 1930s to give you a comparison of their 1d (1 pence) fee.
As a place to stop while walking along the beach to see some history and play games that thousnads before you have used, it's a fantastic place. As a museum, it has an interesting collection but misses out on the opportunity to educate people about the past.