Cheers David, past few days have been productive, I've added a solver to the proceedings, basically, checks if a level is completable when editing it in the tile map editor, and also, I'm using it to "auto play" the level when in game mode.
The solver uses Breadth-First Search (BFS) to find the shortest solution.
This is the reference material I used, and fudged it into BambooBasic to work with the spinny mechanics and stuff:
https://github.com/RajPShinde/8-Puzzle-BFS_Algorithm
Brill reference to get going on the subject.
The difference between BFS and DFS (Depth-First Search, which I also looked at) is that BFS explores all 1-move solutions, then all 2-move solutions, then all 3-move solutions, etc. This guarantees that the first solution found is the shortest possible. A little slower apparently, but in regards to this, it doesnt matter about the speed.
Works a treat! :)
Dabzy