Besides the three included games on the console, other game cartridges could be purchased. Each game cartridge is numbered from 1 to 21, and all have the Discoveries in the game titles as part of the overall game theme.  Each game module has several different modes for different games, and an age range depending on the content.

Although the system was advertised alongside 21 different modules since the beginning, all 21 were not ready at launch, with only 8 titles available by late 1982. Others were developed and released at later dates. To date the following physical game modules have been discovered: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ,12, 13, 14, 16, and 18. With the elusive 16 being the most rare to find out of all the known games. 

Each box is a different color and collecting them together creates a color gradient with the spines. Photos of different children are used in the front of each box. Background shading indicates the color of the box and number on the spine of each game.

The CDS shared many similarities with the Mattel Intellivision, such as names, running man, printing credits and overall design. It remains a somewhat obscure Mattel LCD learning system to this day!