×enter from one of the passages on the left so that I can move a keg, so that I can free the construct. And I suppose I have to drop both trapdoors on the same turns (with the help of the construct) just in the right time when the snake is on the hot tile.

×The pressure plate releasing the snake and the trapdoors are 20 tiles apart and the snake is on a loop of length 16, so it will hit the choice point at (22,31) twice and needs to be on horizontal preference both times.

Since turns n and (n + 15) always have opposite preference, (n + 16) must be the first turn of horizontal preference, i.e. a turn ending in 9.

×I think I can only do that after the blue door is down, and I have to use the seeding beacon, reenter unarmed, and extract a keg. Then perhaps destroy the builders and use the construct to drop both trapdoors?

×
1. Someone or something has to press the one-use plate before the room is cleared. The construct won't do it because of the oremites; I don't have a pushing weapon so it can't be a keg, so it must be Beethro himself, unarmed.
2. When entering at (0,10) unarmed, I can extract one keg. I think that's where I have to enter to get the keycard.
3. When Beethro is unarmed, the only thing that can drop trapdoors is the construct, one at a time.
4. So I thought I have to blow up the builders, but that requires two kegs and I can't get a second one out.
5. If I could get a second keg, I would have to push it on the disabled firetrap, and then step on the pressure plate (or have the awakened construct step on it)
6. But for that I have to spend too much time in the top half of the room with the snake released, and as a result it inevitably gets stuck.
7. But even before all that, I can't get the construct out, for the same reason.

×second keg.

×You can set up the keg to hit the pressure plate on the way back, allowing you to get one extra turn before the snake traps itself.

×Remember that a construct can only push a keg if there's an empty space to push into.

So, in order to retrieve a keg that gets pushed into row 8, something should be at (3,8) to stop the keg from getting pushed into that spot.