The Kettle for this mission is on a platform to the right of Suction-Cup Lookout. To get to it, swim up the platform to the right of the Boss Kettle, and in squid form, use the Dash track. The kettle is on the platform you land on.
The player spawns on top of a walkway leading left, and a pit filled with Octarian ink and three Shielded Twintacle Octotrooper below them. Proceeding forward will cause an Industrial Squee-G to break through a set of crates and gives the player an introduction on how they work: they will move to clean up all ink in an area, and can splat enemies. The player is suggested to simply proceed forward via the walkway, but should the player fall into the pit, they can leave via a Gusher back to the walkway, or an inkable wall in the crevice housing the Industrial Squee-G the player can climb up. The end of the island has a Ride rail that brings the player to the next checkpoint.
Checkpoint 1
Ink the wall and climb up it before the Squee-G cleans it. Splat the Octotrooper on top, and attract the Industrial Squee-G on the other side with bombs, preferably the Autobomb, as they do not roll or move. Hop onto it and throw bombs to attract into going to the other side. Hit the ride rail and proceed to the next checkpoint.
Checkpoint 2
Hit the Gusher to get on top. Walk along the path and defeat the Octotroopers and Shielded Octotroopers on the way. Break the sprinkler ahead, let the Squee-G take care of the mess, and head to the launchpad to the next checkpoint.
Checkpoint 3
Bring the Industrial Squee-G ahead and hop on it. Bring it to the other side so as to get onto the platform with the launchpad. If you fall off, climb onto one of the blocks on the sides or in the middle.
Checkpoint 4
Drop off and splat the two Octotroopers. Head to the right, cross the grate, and climb the structure ahead, splatting the Octocopter and Octotrooper ahead. The top of the structure sits a key and a ride rail to get back. Head to the vault ahead to unleash the Industrial Squee-G. Lure it back to the big platform along the thin passage, move around it, and use the gusher to reach the launchpad to the next checkpoint.
Checkpoint 5
Drop off and get onto the block ahead, to ink and climb up the platform ahead. Splat the Octotrooper and get to the final checkpoint.
Final Checkpoint
Splat the Shielded Octotrooper and break the crates behind it to the right. Grab the key from the crates, unlock the Industrial Squee-G, then either board it or head up the passage on the left and let it scramble with the Shielded Octotroopers and Octotroopers. The player will eventually have to get on the Squee-G to ink and get on the platform with the Zapfish.
Collectibles
Sunken Scroll
“
Many travelers find themselves in Inkopolis Square at some point in their journey. Youth from far-flung seas gather in this colorful hub of comings, goings, meetings, and farewells.
Location:
After Checkpoint 3, get past the giant Squee-G, and once you get onto the T-shaped platform with the launchpad, look for an opening on your right. Jump down through the opening and go left to find the crate with the scroll.
Scroll location
Sardinium
Location:
After Checkpoint 5, get onto the platform with the key to open the door of the cage of the Squee-G, and ride the inkrail back. Jump at the end of the rail onto the glass platform that holds the Sardinium.
Sardinium location
Armor
Back-Alley Cleanup has 4 pieces of armor to collect.
Armor 1 Location: The first piece of armor is on the giant Squee-G after checkpoint 1.
Armor 2 Location: The second piece of armor is on the grate to the right after checkpoint 2.
Armor 3 Location: The third piece of armor is on the giant Squee-G of checkpoint 3.
Armor 4 Location: The fourth piece of armor is in the crate directly to the right of the final checkpoint.
