Inspired by your example I just had a go at creating a mountain climbing game in similar fashion and I agree it does well on the concepts but there are lots of bugs in the details. For example it referred to certain divs by class and id but failed to assign class or id attributes to the respective divs. Maybe there are separate elements generating the response that do not always know exactly what the other has generated. Given the elementary nature of the bugs it should be easy to add a code review element that can find and fix these bugs before presenting the response to the user. When I pointed out a failing it regenerated a new different version of the code responsible but missed the cause of the bug.