The wall class works fine in the task it was created for, but I did try some experimental stuff by creating walls starting from even coordinates (to avoid wall created next to each other). This is how it looks after filling the level (which for testing purposes is just the lighthouse beach).
Let's point out that it doesn't look that great as a maze and also I think it could create closed areas, I guess. But maybe it could be something useful when creating ruins with larger grid. Only some walls would remain from what once was a great civilization.
The plan for now is go through each level theme and add whatever they require. I think it's a good plan. Testing for level scale (now that levels can have different sizes) has been fun, when you see how the generation routine fails to work in both too small or large levels. Teemu is also a nice project in a way that there is almost certainly something you can add to level themes to make them just a bit more interesting.