* Then, once move is applied disallow moving the stone again without re-engaging it a new tap/click-hold? Or undo the last move silently if the following move is the reverse of the preceding one?

* I meant "implied" light source. My point was that visually it's somewhat messy due to shadows being on top.

Re: the starring thing - I can't reproduce, but 100% saw it. Was on the level 3.