PuzzlePiece RandomMovement(PuzzlePiece invisiblePiece, PuzzlePiece exceptPiece)
{
List <PuzzlePiece> selectablePieces = GetNeighbors(invisiblePiece);
selectablePieces.Remove(exceptPiece);
int randomIdx = UnityEngine.Random.Range(0, selectablePieces.Count);
PuzzlePiece selectedPiece = selectablePieces[randomIdx];
selectedPiece.HandleClickEvent();
return(selectedPiece);
}