I returned to this project yesterday. I am designing the navigation system for the junk, one that uses coloured buttons and a map to lead the user round a number of locations at sea. The view outside the cabin and from the deck has to be consistent, with the appropriate angles of buoys and the island. These will have to be installed as sprites, so that we don't have to make a scene for every viewpoint.
The cabin of the junk, from which navigation takes place, looked so stark that I'm installing a carpet in it.
I still haven't figured out how to organise the puzzle. I don't want just a maze or point and click shooting gallery. There has to be some substance to the puzzle that looks soluble but isn't too easy.
Once I get the navigation in place, I'll do another test version. Watch this space.