Just looking at this now...
The sound played after successfully finishing a tutorial level sound of: "DAH-Dah-dua" (high to lower pitch) sounds like I failed. I might recommend choosing a different sound effect.
Update:
The 'Guards Spooking each other' puzzle indicated the logic, but not the guard entities themselves. I was assuming we were making automated systems --not using flesh and blood guard people. This paradigm is now a bit confusing.
I think I understand what you're going for in terms of logic, but the narrative is hard to imagine. I get that a 'zone' isn't a person, but the boundaries of a 'detection' of people... for if there were human guards, they would obviously spook eachother as they were walking their zone perimeter. The tell that this is something different is that an even number of overlaps is perfectly alright. You're going to need to improve this explanation so the game world feels intuitive.