That One Puzzle: A few puzzles are quite hard, like the Fire Puzzle in the spider realm or the programming puzzle in the Bismuth realm, but the very last one takes the cake: 16 yellow buttons guarding the crossover switch, half of which are fake and if you click any of those, they move and change their positions. You're supposed to hit the buttons that did NOT move, but because all of them look the same, it's VERY hard to keep your eyes on the right ones! Worse, there's no set pattern, and each movement of the camouflage buttons is random. The Conductor almost mocks you about this after you solve it and flip the switch to human control.
"...The camouflage I placed upon the toggles has delayed you long enough."