I do have a pulsing effect going on with the glow shader that I think should be pretty straightforward to adapt into a flickering effect like that. Originally, when added the ambient hvac noise, there were supposed to be multiple instances of it producing positional audio from all of the dead ends - but in practice I could only get one instance of the sound to play (instead of however many dead ends generated into the maze), so with the jam time running out I settled on just having the hvac noise come from the center of the maze. I wish at that point I would've thought to set it at the exit to maybe give a subtle clue on what direction to head once the exit is active. I do still have a list of dead end coordinates generating along with the mazes - it'd probably be pretty easy to get the odd spooky impact noise to come from those every now and then...
Anyway, thanks for trying it out and I'm glad you enjoyed it!