Fun concept, but the level of precision needed is ridiculous. When the solution is obvious, but I can't move the pieces because of a one pixel difference = dumb...2/5 until that is fixed.
The timer is stupid and you should be able to pick which end you want your domino to go when there are multiple options. Often my strategy got screwed up by stupid placement.
Instead of the mouse moving the borders of the map, perhaps you should make it so the arrow keys or wasd moves the map and then clicking with the mouse would be more accurate.
Corrected! (new version uploaded)