Early games frequently took the approach of inventing an interpreted machine code in which the bulk of the game would be written, with an assembly interpreter that would need to be rewritten for each target IA and modified for the specific peripheral mixes of each target machine.

The approach runs slower than a game written directly in assembly, but the cost to port to different architectures is much lower.

Sort of like Electron trades off native performance and look-and-feel to make multi-platform apps much more achievable.

IMO the OS vendors failed everyone by refusing to even attempt to agree on a common API for UI development, paving the way for web browsers to become the real OS and, ultimately, embedded browsers to be the affordable and practical way to be cross platform.