I was bored, and wanted to see how the pathfinding would hold up under unusual circumstances. So I built my colony thusly (a), and played for a while, and proceeded to harvest eggs en masse. When the eventual invasion arrived, it was 42 Fishmen strong (b). Good new, nothing got stuck in geometry, and nothing crashed or froze during the invasion. Thanks to my rat maze, I was able to fend off 42 Fishmen with about 15 soldiers and militia. My losses came to 5 poor souls, mostly killed through walls while they were sleeping. Then I built a graveyard, and my game crashed. (a) (b) I built all my buildings along the ridge where the beach meets grass; all my structures incorporated turns and forks in their layout, so the only ways to pass through were a series of narrow, twisty alleys. I ran a large Fishman invasion through the resulting maze, and it was quite effective, in that it forced the invaders to run back and forth in front of my soldiers' guns.
I suspect you could; it would consume a lot more wood, but it would have the advantage of not having colonists inside.
I love that your update message in the bottom right reads, "Some immigrants have arrived." Errrr, sort of, yeah.
