Hmmm... now you've got me wondering. Thing is, on the later levels, I found myself working one property at a time, understanding the effect of that one property

Hmmm... now you've got me wondering. Thing is, on the later levels, I found myself working one property at a time, understanding the effect of that one property, and building up the complete 'answer'. I'm not sure that handling the 'wrong answer' as a special case works for this type of approach. The repetition should (and is, to an extent) be provided by subsequent questions reusing just-learned knowledge. There's nothing to stop you starting from the beginning at any point, or starting from scratch at any point in future. It makes it less of a 'game' but, like I said, I think you're overplaying the game element.