Game publisher Aspyr is ceasing sale of its 32-bit Mac game catalog on Tuesday, with Monday being the last day the company is offering the titles for purchase, citing Apple's shift of macOS to 64-bit and end of support for 32-bit as the reason for the change.

Apple has warned for some time that it was discontinuing support for 32-bit applications in macOS, with the recently-revealed macOS Catalina 10.15 being the first version of the operating system to work with just 64-bit apps. High Sierra was the last to support 32-bit apps fully, while the current macOS Mojave will be the last to support 32-bit applications at all.

Due to the change, Aspyr has confirmed it too is ending support for 32-bit applications for future operating systems. From Tuesday onwards, Aspyr's remaining 32-bit Mac library will become 64-bit or receive a 64-bit update by September, in time for macOS Catalina's public release.

"Once Apple announced it was discontinuing support for 32-bit titles, we decided ending sales for those games was the right thing to do, and well before Apple's support ends later this year," said Aspyr vice president of publishing Elizabeth Howard. "Giving players fun, innovative games across all platforms is our focus, and we have some exciting new projects that we will reveal very soon."

The company has published a complete list of 32-bit games that will be removed in its support pages. Its complete game library is 190 games in size, with many already 64-bit compatible or will be in the future.

The lis of games being removed includes "Borderlands: The Pre-Sequel," five "Call of Duty" titles, "Civilization IV" and "Colonization," "Duke Nukem Forever," four "Star Wars" games, and a selection of others.