Both yes and no, you coded to the hardware, the lack of abstraction meant it was easy to make it do what you wanted it to do, the only downside was there wasn't as much transferable knowledge between systems. Nasir worked a lot on Apple 2 games so already knew the 65C816 instruction set, so it sounds like he just had a fun time making these, but he was definitely a great coder!
Modern game development is much more complicated, just to make a simple ass game you need to know C/C++, a shader language, a rendering pipeline, plus all the SDK libraries, networking/online stack, honestly, if I had a choice I'd go back to making SNES games.