A quick progress update:

• Rewritten the graph system for cables because in version 1, all pylons were connected to every other pylons, which isn't very practical.
• Cables can now be activated by pulling on them, or by direct contact from the player (easier).
• When a cable is activated, it can be used as a transport accelerator.
• If all the cables connected to a city (sphere) are activated, it becomes a gateway (cube) leading to a strange and mysterious world populated by aggressive, detestable creatures (and probably treasure, otherwise what would be the point?). I don't have many ideas about it yet...