Most likely stuff like DirectX 12, or third-party middleware without viable MacOS or Linux support. The deprecation of OpenGL on MacOS is another barrier for t

Most likely stuff like DirectX 12, or third-party middleware without viable MacOS or Linux support. The deprecation of OpenGL on MacOS is another barrier for that platform - you either have to buy GL-on-Metal middleware from someone or write a new Metal renderer. If the % of customers on Mac is small enough I can understand just opting to drop that platform. Hard to say re:Linux, though. Maybe they get more customer service burden out of maintaining Linux support than they do revenue. It's common to hear that from indie game developers, though some developers say the opposite. EDIT: Also just occurred to me that Valve's ongoing Proton efforts have resulted in Windows Rocket League working okay on Linux: https://www.protondb.com/app/252950 https://www.protondb.com/app/252950 As a result the devs may have decided it's better to just leave Linux to third parties. Some of the reviews claim Windows-via-Proton is faster than the official Linux port!