I think the flag levels in this game are stupid. The reason is quite simple: Despite coding the right solution for my hero to pick up the flags and place the right building (fence or fire-trap), a simple misclick on the flag or not being fast enough, or not seeing the "X" bounce (which seems to happen every other time in Sarven Sentry), or the archer never calling out a Yak! (which just happened the 4th time playing this despite a perfect playthrough up to that point) can lose the level for you and prevent progression.
I started playing this game because of the gentle learning curve and ease with which it teaches you very basic concepts about coding. Good job with that. Reflexes or requiring people to click accurately stray into the realm of "real" video games and away from education. Maybe you thought that it would break up some monotony, but that is not why I play this game.
Introducing an arbitrary difficulty based on reflexes (I suck with the trackpad and I'm sure most people do as well at the same time as thinking about whether or not their solution will work) is bad learning design. It breaks up the flow of learning and causes annoyance with the overall experience.