The Stack

More than a week since my last post! I’m still playing The Second Sky, but I’ve slowed down considerably. I don’t play every day, and when I do, I consider it a good session if I finish even one room. A far cry from my reaction to The City Beneath.

It’s all because the puzzles — or at least, the endgame puzzles, which are still somewhat optional unless you’re stubborn enough to insist on the best ending — are so much harder this time around. Before this game, Journey to Rooted Hold was definitely the most difficult, even if you ignore the Challenges that consumed so many days on this blog. And given how much easier Gunthro was than The City Beneath, I really wasn’t anticipating such an extreme reversal. But it makes sense. We’re at the final chapter of the final chapter. If you’ve come this far, you’re an expert on everything the puzzle designers can throw at you. That means they can freely exploit minutiae like movement order.

See, every monster has a number, which you can see when you right-click on it. When you move, the monsters move in order from lowest to highest, and this can have effects on what happens. Consider a row of Roach Queens lined up against a wall, as in the screenshot. Roach Queens run away from the player, and prefer north/south to east/west movement when they’re blocked from moving diagonally. What happens when you move one square to the north? You can’t answer that from the screenshot; there isn’t enough information. If they’re arranged from east to west, such that the easternmost one moves first, then each roach will simply move one square southwest, except for the last, which will have no empty space to move into. The next turn, the same will happen again, except the last two will be blocked, and so forth until they’re all hugging the western wall. But if they’re arranged from west to east, the leftmost one will move south first, then the next one will be unable to move southwest and instead move south, and so forth. They’ll remain in a horizontal row and march south in lock-step.

The latter is in fact what happens in this puzzle, and it’s pretty easy to keep the roaches neatly ordered as you chase them south, then back north, then southwest, timing your actions to their spawn cycle. Which is good, because you need them in a row at the very end, for reasons I won’t go into. But before you get there, the geometry of the room acts against you, splitting the first and last roaches out of the line. By the end, you need to get the roaches in a different order, probably 3124, presumably by using the right-hand walls in just the right way. The uncertainty of my words comes from the fact that I haven’t yet solved this puzzle.

I’ve known since the very first DROD that movement order can make a difference, but I never needed to pay attention to it precisely. “Move these guys against walls some to get them to shuffle around” was always adequate. Here, I don’t just need to know movement order, I need to deliberately manipulate it. And that’s what this chapter is like.