+1 to this. It's also visually confusing, the gate looks like it's covering two cells.
Great game! Feature request: add a button that shows my submitted solution. I'd like to be able to compare it with the optimal solution (so it'd be nice if a single tap could toggle between my submission and the optimal).
It would be nice if the “optimal” view visualized both my solution and the optimal one at the same time, like a Venn diagram.