How do you answer the dreaded "How close are you to finishing your game?" question?

I'm sure this is a problem other indie devs face, which is family members, friends, and acquaintances asking

"Oh, how far along are you in your game?" question, when personally, I never have the slightest clue. I have a rough plan, a lot of assets, and a lot of coding, but I'm not really "At a stage" you know? I don't even know if I'm over the midpoint or not. That's not how my creative process works, but everyone I talk to seems to hate that answer.

I usually just lie and say a random percentage, but recently people have realized that my percentages never make sense. So does anyone have a good answer?