Cassette 50

Cassette 50 (released in Spain as Galaxy 50 - 50 Excitantes Juegos) is a compilation of games published by Cascade Games Ltd in 1983, and is an early example of shovelware - computer software marketed primarily on the basis of its sheer quantity rather than other factors such as quality or playability. The compilation was available for many of the microcomputer platforms of the time.
The compilation was heavily advertised in home computer magazines, with buyers also receiving a Timex digital calculator watch with each purchase. 
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".
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.
Content.
The games featured differed depending on the platform. Some like "Star Trek" and "Maze Eater" appeared on all versions. Some like "Lunar Lander" were ports or clones of very early or popular games, while others were sourced from independent developers. Some games that had the same title were entirely different depending on which version. Some also had playability issues.
Acorn Electron / Commodore 64 / Dragon 32 / Oric-1 / Oric Atmos / ZX81.
The games "Exchange" and "The Force", although listed on the inlay, are missing from the Acorn Electron version, meaning only 48 games actually appeared on the cassette. There was a second release of the Dragon 32 version which had different versions of some of the games. "Tunnel Escape" on the C64 version is credited as such in the game's inlay but is credited as ""Escape or Bust" in the actual game.
BBC Micro.
The game "Dice Thrower" is mistakenly displayed in the inlay as "Do Your Sums"" .
ZX Spectrum.
The number with the '#' symbol represents the order in which the games appear on the tape.
'Star Trek' appears in the cassette booklet as 'Startrek', and 'Jet Mobile' appears as 'Jetmobile'.
Reception.
The games, almost without exception written in BASIC, were deemed to be of poor quality. They have been described as "so bad it caused physical discomfort", "beyond awful", and "a piece of crap collection". The poor quality of the games inspired the annual Crap Games Competitions (for example the comp.sys.sinclair Crap Games Competition and the C64 Crap Game Compo) and a now-defunct site reviewing bad games.