zlacker

Ok, sure, if you already wrote your game to be cross-platform, then porting it to one of the platforms your libraries support may well be trivial. That feels almost tautological and the precondition you've set up here doesn't apply to most games.

SDL2 is a great library, and many good games have been built using it. But then your target platform is not Android at all, it's SDL2's platform-agnostic abstractions (plus OpenGL or Vulkan if you're doing 3D graphics). And you still may run into input handling issues if you didn't think carefully about the differences between mobile and desktop.

Then, to achieve something like the binary compatibility Windows already provides, you'll need to statically link your executable on Linux. That definitely means no GNU because virtually no game developer is going to allow themselves to be forced onto a copyleft license.