Completing the Mission achievements

Completing the Mission has a total of 27 achievements unlockable.

Endings
These achievements are achieved by getting all 16 possible endings for the game. See the articles for the endings for detailed walkthroughs.

Easter Eggs
These achievements are achieved by finding easter eggs in the game.

Assemble the Crew
Find all 12 hidden Among Us crewmates found throughout the episode:
 * Master Bounty Hunter: after using Convert, Henry's squad enters the warehouse. The Red crewmate is next to a cabinet.
 * Cleaned 'em Out:
 * When Henry jumps off the Toppat Train as it arrives at the launch site, the Yellow crewmate can be seen on a crate.
 * When Henry is in the rocket and uses Leafmöde, the Blue crewmate is on a crate behind him.
 * Toppat 4 Life, if Ellias Bahtchin orders Phantom to nuke the military camp, the Green crewmate is located next to Phantom.
 * Toppat Civil Warfare, when executing the Midnight Surprise plan, the Pink crewmate is seen in the ventilation duct with the electrical defense.
 * Capital Gains, when Henry and Ellie wonder how to empty the money cart of the wrecked Toppat Train, the Orange crewmate is seen among the gold.
 * Revenged: At the start of the story, when Henry wakes up on board Dr. Vinschpinsilstien's ship, the Black crewmate is next to his bed.
 * Free Man: When Henry uses the Remote and gets ejected into space, the White crewmate can be seen floating in space.
 * Jewel Baron: The Purple crewmate is in the vault of the Toppat Orbital Station. He can only be clicked just after Henry teleports inside after choosing Teleporter.
 * Triple Threat: If Henry and Ellie use Parasols to land on the control tower, the Brown crewmate can be seen inside the tower (far right).
 * Valiant Hero: The Cyan crewmate is in the luxury escape pod during the final choice screen.
 * A Tan crewmate can be found in the Trash Ball. Tan is not needed for the achievement, and clicking on it will create a fist that punches it away. This references the development of Among Us, where Tan was considered but ultimately rejected. Interestingly, Tan would later be re-added to Among Us in 2021.
 * Stickmin Space Resort: When Icepick and Sal Malone are arguing about switching hats, the Lime crewmate is in the open truck to the right.

Lockpick Pro
During the second choice screen for "Free Man", keep using the Lockpick six times until you get the proper fail.

Speedrun Strats
During the "Toppat 4 Life" pathway, when choosing the Walkthrough fail, end the walkthrough as quickly as possible by spam clicking.

Play of the Game
During "Revenged", after getting the fail message for "Absorb", click on the Play of the Game words highlighted in blue.

Respects
During "Cleaned 'em Out", after the Mannequin fails, press the "F" key on your keyboard and if this method doesn't work, click the letter "F" on the actual fail message.

BRRYYESS!
During the end credits for "Capital Gains", click the setting sun to reveal a Shoop da Whoop.

This is fun!
During the "Triple Threat" pathway, in the second choice screen, use the Swap option 6 times in a row. Charles Calvin will call Henry and Ellie out on their goofing around instead of focusing on the mission.

Greasy Delight
During "Valiant Hero", after losing the Hot Knife, click on the "Butter" in "Butterfingers?".

Multiverse Correction
Get the secret Multiverse Correction cutscene. The procedure is as follows:
 * 1) Get every single fail and ending in every Henry Stickmin game.
 * 2) Head to the Toppat 4 Life route.
 * 3) When at the final choice screen, click on the sticky notes until a meter marked Multiverse Imbalance shows up.
 * 4) Press the button marked FIX.

The Story Ends
Get all 164 unique fails in Completing the Mission. The achievement's name is an reference to "The Story Begins" medal from Breaking the Bank.

Allies and Enemies
Find all 222 bios in the game.

Trivia

 * The Assemble the Crew achievement's description is possibly a reference to Super Smash Bros. Ultimate's arguably most famous line, "Everyone is here!".
 * In the same achievement, the pink crewmate's location is a reference to the impostor's 'venting' ability.
 * It is odd that there is a Tan crewmate, but not a Fortegreen crewmate.
 * The Greasy Delight Achievement is a callback to Infiltrating the Airship's achievement "Buttery Snack".
 * In BtB, EtP, StD, ItA and FtC, achievements are known as ranks but in CtM they are known as endings, foreshadowing the saga's end.