It is a neat game. With a bit of trying you can find some patterns:
* Every tile has two orientations 0 and 180 degrees which allows to cut a lot of possibilities for small fields.
* Three tiles can be flipped together, meaning if you have one or two tiles unsolved, your idea won't work out.
* Large fields have more solutions.
Sadly I found some bugs:
* World generation does not work correctly: there is an unmovable field (nice idea!) but during generation it gets moved. This makes some puzzles unsolvable. The randomizer should ignore this field.
* The undo function has some issues undoing the wrong move or skipping a move. Fully undoing a puzzle does not always result in a solution. If this happens while you're playing you get locked.