Mac gaming has come a long way, with more and more games supporting it by default. Older games may be in trouble, however. A new macOS called Catalina is coming out this month, and it won't support 32-bit apps by default. As game maker Paolo Pedercini points out on Twitter, that includes not just old games but basically anything made with Unity before its 5.5 update in 2016. And a lot more games were made with Unity than you probably realize.

Next week I'm going to post a guide on how to keep old flash games alive. SWF files can be packaged into executables (aka projectors) but Adobe disabled that function before they switched to 64bit. This is the only workaround: https://t.co/ZvBdsuJDgkHere goes my sabbatical...September 3, 2019

Developers can of course update their games to be 64-bit compatible, but that's not always possible—whether because the studios that made them no longer exist or it's not cost-effective. Jake Birkett of Grey Alien Games says, "I may not release any more games on Mac because of this."

A similar problem affects iOS apps, which are frequently abandoned because the cost of updating them for each new iPhone becomes prohibitive, especially for small studios with a wide catalogue.

MacRumors explains the process for checking if a program will stop working under Catalina, which will obviously affect all kinds of programs as well as games (Adobe's Lightroom, for instance), and even entire file types.

Before those of us who stick to Windows get too full of ourselves, there's no promise Microsoft's OS will support 32-bit games in future versions either. So that's something to look forward to.