The game around this game is the game.
The author provides the source code for this game on the game's website, but it's in the form of an image, and the source is minified so as to make it harder to read.
Luckily, Ant Hope did the hard work for you, analyzing the source.
And it turns out, your choices have no effect. (If you played this game like I did, pressing enter for Y on every turn on your first playthrough, you probably guessed as much.)
The instruction manual and strategy guide are deliberately misleading about this, but, in hindsight, their awkward phrasing includes subtle hints that your choices have no consequences. Like this passage from the intro:
If you allow your imagination to help you elaborate each stop on your journey, and if you truly get into the mindset of the returning wanderer, Amazing Quest will offer you rewards as you play it again and again.
So, this game leaves something to be desired. But the meta-game has a puzzle: decode the source code. And now I've spoiled it for you.
But the meta-game also has a toy: play Amazing Quest and use your imagination to tell your own story with it.
If the documentation had been more honest about the game's purpose ("it's a little procgen ditty for the C64; see if you can imagine your own story to go along with it,") I could have given it a better rating.
But instead, I claim that it's a prank, a joke played on the player. I appreciate that the prank is a puzzle with a solution, and that there are even some clues to help you solve the puzzle. But IMO this game, this prank, treats its players disrespectfully.
This game would be 100% better by having players opt-in to the joke, so we're all in on it together. As it stands, you, having read this review, can now enjoy Amazing Quest on its own terms, though you probably can't enjoy the process of decoding the source, not now that I've spoiled it.