Fun fact: if you wanted, you could make even more compact games on a modern computer using procedural generation to cut down on resources. (way too heavy and ram consuming for old consoles)
If one want to see what you can do with limited executable size on a modern computer, I suggest googling for "4k demo", and prepare to be amazed
(thats 4096 bytes, including all code and resources)
Those guys even compress/generate their code...