Cassette 50 (in Spain released as "Galaxy 50 - 50 Excitantes Juegos") was a compilation of games published by Cascade Games Ltd. The compilation included a Timex digital calculator watch.
According to the instructions, "the games will provide many hours of entertainment for all the family at a fraction of the cost of other computer games". The games were universally considered awful.
In an interview, Matthew Lewis, the author of Galaxy Defence, said he wrote the game when he was 14 and submitted it in response to a small, anonymous ad in a local newspaper. He was paid £10 for his game, but he had to give up all rights to it. Galaxy Defence took 12 hours to code and the graphics were done by his father, Ernest Lewis.
Read more about Cassette 50: Reception