Brilliant little puzzle game, well done. I've been trying to create solutions that use very little space by placing the building inside each other and ending up with a grid of nodes.
https://imgur.com/gallery/jbA5ajM
I did isolate a bug. If you try to connect a node to one directly above it (two vertically adjacent nodes) the game crashes. I'll post the error message below. Here's a screenshot demonstrating it, the example that caused the error is on the far right.
Thank you for such a great game!
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ERROR in
action number 1
of Step Event0
for object oControl:
local variable (null)(100854) not set before reading it.
at gml_Script_SpawnConnectors
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gml_Script_SpawnConnectors (line -1)
gml_Object_oControl_Step_0