Thanks for your nice review !
Following the theme is what makes this jam fun. I've played as well other (good) games that used only a Halloween theme while it was not the goal.
Concerning the mobs, I wanted them to get to the TV that was activated ("the bonus that turns against us"), but I needed path finding and I could not train me on this with the time I had left. In addition, I wanted the mobs to wander instead when a TV is activated, but only the first one reacted, the other 2 ones stayed still. I don't know where this is coming from, I may have missed to connect a signal. I'll have to fix that in the future.
I notice on your screenshot that the web build is missing one light at the end of the corridor, and there are other display issues. The desktop builds look as expected. May be due to Godot using a less powerful engine on web builds ; I'll work on that as well.