During the previous century of human civilization, computer games were primitive enough that their entire codebase would fit into a few pages of a magazine. You could play the game by manually retyping the codebase into a text editor.
In the 90s I got an Amiga and discovered the demoscene (basically showing off as mentioned in another comment).
Fast forward another decade and bored at my parents after finishing Uni I dragged my Speccy out of storage and managed to get the Tim Follin music routine running! And found an assembler and did some Z80 assembler demo effects for the lulz.
As you said: good times.