I've been reading up on an archaic assembly language used on the original Nintendo and early Super Nintendo games and gotten the basics down. I've found a emulator that lets me test scripts, and written some basic functions like loading a number to A, loading a number to B, multiplying A by B and saving the result to X, etc. etc.
what I'm wondering is, can someone explain to me in layman's terms how games were written entirely in this assembly language for the NES? So far what I'm seeing is an entire language that's more or less designed to edit, move, save, load and perform functions on numbers, and I don't understand how they used this language to produce things like music, graphics, text, and all the other things that make a game a game.