But as soon as you are just a tiny bit off the beaten path, Fable/Sol will go postal regularly. So if your indie game has interesting gameplay mechanics, nobody will be able to 1-shot that for a long time. (Because their prompt would have to include everything that’s unique to your game.)
Well, yes. You need to unambiguously describe what you need to be built. That's not a problem this going to take 'a long time's to solve.
In the limit this can be as complex or more complex than just writing your program to begin with. If you actually care about your implementation details, your specification will balloon to encode all of them.