Octodad: Dadliest Catch/Toilet and Trouble

Toilet and Trouble is a secret level that can be accessed via the ../Aquatic Fun Center/ stage in the main game. In the men's room, flush Octodad down the toilet in the center stall and you'll enter this side-scrolling level. If you attempt to do this in free play after having beaten the game, the stage will end, but Toilet and Trouble can then be accessed from the free play menu. As for the actual layout of the level, Octodad will have to start by climbing up some pistons and then moving across some large wheels. At the end of this path is a button that he can press to ascend a lift. Jump across to the platform at the top. Past a rocky bridge is a platform attached to a wheel. Instead of attempting to climb up the other wheels, quickly move under the giant wheel to be launched upward and forward. Proceed under the big wheel and climb up the ladder on the wall. From here, Octodad can move across small platforms hanging from the ceiling by hanging his legs off the edges and swinging from platform to platform. Be careful not to fall on the wheel here, as it will simply send you back down. Once you reach the last platform, Octodad will be able to reach for the button; pressing it will alter the position of the wheels, allowing him to proceed along them.

After squeezing Octodad between the wheels so that he's launched upward, then walk over the smoke by the wall to float toward the spinning contraption. Use it to reach some pipes bellowing more smoke. Past them is a ladder that you'll have to move under, so that Octodad can climb up the other side and reach the exit. Near the exit are three ties that you can pick up as a reward for completing the secret level.