How is the weather, and are you inside or outside? An idea I would play with to keep the advantage of an open air maze but keeping the cave atmosphere is what I would call a half arch. The idea being to make the top part like an arch but leave a 2 foot wide air gap. kind of like this:
Making it irregular, maybe some 4 foot completely covered strches, but discontinuous.
Least that is what I would do for mine