Adorable little game!
Since you plan on releasing a 1.0, you might want to take a look at this message I got after a crash (as you can tell, I was trying to delete a connector).
___________________________________________
############################################################################################
ERROR in
action number 1
of Destroy Event
for object oConnectorParent:
PerformEvent recursion depth failure - check for infinite loops, check objects for parenting
at gml_Object_oConnectorParent_Destroy_0
############################################################################################
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oConnectorParent_Destroy_0 (line -1)
gml_Object_oControl_Step_0 (line -1)