Return of the Octarians

Return of the Octarians is the first mission in single-player mode, Octo Canyon.

Location
The player must speak to Marie in Inkopolis Square to access Octo Canyon. The kettle for this mission is straight across the first island, behind the first boss kettle.

Beginning
There is a chain of three Power Eggs in an already inked ramp leading to the first launchpad.

Checkpoint 1
Ahead is a downwards slide. Shoot forwards to collect the first four Power Eggs leading to behind a wall, and to the sides to collect another 2 Eggs on each side (for a total of 8 Eggs).

Heading further down the ramp, collect another two Eggs in front of two walls. The Octotrooper cannot hit you behind either wall.

Shoot the Octotrooper. A Squid Ring will appear. Jump through the ring using to collect a Power Egg from it.

Follow the ink to the next area. A Shielded Octotrooper is on guard. Use a bomb to distract the trooper, then shoot him from behind. A launchpad appears, but before launching, break the boxes to the left for a Power Egg. Use the launchpad.

Checkpoint 2
The launchpad lands you above three Octotroopers. Do not jump down; simply shoot or throw a bomb from above. When dead, a line of three squid rings appears. Jump through them to the bottom.

Follow the path around to the left. There is an orange box, break it for a Power Egg. Around the corner is an Octotrooper and another orange box with a Power Egg. Kill the trooper, and continue following the path left.

There are five Octotroopers in a pyramid shape on top of boxes. You can easily kill them by throwing a couple of Splat Bombs. You can get another three Power Eggs on the side and the boxes give another two. A launchpad appears after killing the troopers. Launch!

Checkpoint 3
You land on the platform just above. Shoot the orange box to the left for a Power Egg. Ahead is a Balloon Fish with eight Power Eggs around. Simply pop it. Further ahead is another two Octotroopers, one with a balloon attached, and a Vault. Popping the balloon grants five Power Eggs.

After killing the two troopers, head to the left, collecting the two Eggs on the way. Swim through the grate using squid form. Use the Balloon Fish to break the crates to get six Power Eggs and release an ambush of 3 Octotroopers. Kill them easily by popping the Balloon Fish again. Swim back towards the Vault and across, collecting the two Eggs on the way and swim through the grate. Smash all the boxes for three Power Eggs and release another three Octotroopers. Kill them. Behind all the boxes is a taped orange box which is stronger than the other ones. Destroy that to get the Key. Pick up the key and swim back to the vault, and launch.

Checkpoint 4
Head off the top to behind the row of boxes, collecting the two Power Eggs on each side. Break the two orange boxes for a Power Egg and an Armor.

Ahead are six Octotroopers. Use bombs to kill them. If you run low on health, hide behind the wall or pillars. Collect the six Power Eggs around, and one on top of each pillar. There is also a taped orange box containing a tin can for another 10 Eggs.

After collecting these, head to the back of the purple inked area where the final Octotrooper was. Two more Octotroopers spawn in. Kill them.

Checkpoint 5
Destroy the orange box to the left for an Egg, and the small one to the right for another. Collect the three Power Eggs on the field. Ahead is a Shielded Octotrooper. Toss a bomb to distract him, then shoot him in the back. If you find this hard, continue shooting the trooped and eventually the shield will break.

A launch pad appears, but before launching, ink a path up the sides to above the launch pad. A box on top contains a Sardinium. Then use the launchpad.

Checkpoint 6
Jump through the Squid Ring. Three balloons appear. Shoot them, and three more appear. Destroy those too (Marie will comment on it!). Continue along the path and shoot the Balloon Fish ahead. Fall through the grate in squid form through the three Squid Rings. Do a U-turn around the corner facing where you came from. There is a hidden T-ledge down the bottom. The metal grate in the center is inkable; ink it, swim up, and break the orange crate for the Sunken Scroll. Head back through. There is a Shielded Octotrooper patrolling that you can see through the glass window. Sneak up behind or use a bomb to kill him.

Continue forward, destroy the three brown boxes ahead. Ahead is a Balloon Fish, use it to destroy the boxes and release two Octotroopers and one Shielded Octotrooper. Kill them easily using the Balloon Fish and a bomb. When they are dead, a launchpad appears. Launch.

Final Checkpoint
Ahead are two orange boxes; the one on the left contains Tenta Missiles, and the right contains Armor. Collect them. Kill the four Octotroopers guarding the vault. Do not use your special for this for additional Eggs at the end of the level. When they are dead, one will drop a key.

You can use the special on the 12 Octotroopers ahead. Head back, unlock the vault, collect the other Tenta Missiles special inside. Finish off any remaining troopers ahead. Each set drops one key, to unlock each of the three vaults. The front two vaults contain cans for 10 Eggs each, and the last is the launchpad.

Launch, and grab the Zapfish by smashing the shield (easiest by throwing a bomb to break it instantly).

Sardinium
Location: Return of the Octarians's Sardinium can be found before jumping the launchpad from Checkpoint 5 to 6 by first inking to the top above the launchpad.

Sunken Scroll
Location: Return of the Octarians's Sunken Scroll can be found after jumping down the tower and making a U-turn at Checkpoint 6. It is located inside a orange crate.