To achieve 100% completion in Mouthwashing, including all hidden and optional content, you will need to follow a structured approach that encompasses unlocking all achievements, understanding the intricate story, and exploring every environment thoroughly. Below is a detailed guide to help you through this process:

Achievements and Secrets

1. Start the Game (I Hope This Hurts): Simply starting the game will unlock this achievement, introducing you to the whimsical yet haunting world of Mouthwashing.

2. Find Employee Cards: Collecting all employee cards is crucial for completion. Here’s where to find each card:
– Anya: Located in the crew quarters; search thoroughly in drawers or behind objects.
– Curly: Head to the mess hall; look around tables and cabinets.
– Daisuke: His card is near his workstation. Inspect the area carefully.
– Jimmy: Search his quarters thoroughly; look in all accessible locations.
– Swansea: This card can be found either in the cargo bay or close to the control room; explore both areas.

3. Sock Puppet: During Curly’s medication sequence, frequently open and close his mouth. This quirky interaction will unlock the achievement.

4. Friendly Introduction: Seek out Curly as he hides next to the TV in an earlier scene. This scene may require careful observation to trigger.

5. Developer: You can open the developer console by pressing the key typically set to `~` or `F12`. This can unlock further game options or insights.

6. Taking Notes: Successfully open the Pony Express Protection Kit without returning to the cockpit to achieve this.

7. Any% Glitched: A speedrunning challenge! Grab the Mouthwash bottle from Polle within 35 seconds after starting Chapter 14.

8. Cheater: Open the cargo bay door before you obtain the Code Scanner, revealing a cheeky aspect of the game mechanics.

9. Wasteful: Mix the Pony Express Specialty Mocktail during Curly’s birthday party; be observant of the available options.

10. The Good Ending: Interestingly, you need to be killed by Swansea 10 times in the graveyard to unlock this ending.

11. Trickshot: In the graveyard, perform an impressive maneuver—spin 360 degrees before shooting Swansea to hit the achievement.

12. The Name Of The Game: Simply utilize a bottle of mouthwash at any point in the game to earn this.

13. Yimpy: Lock eyes with Yimpy for 10 seconds; this might require waiting for the right moment during gameplay.

14. Go Home: Having reached this point, you can finish the game to claim this final achievement.

Story and Lore

The narrative of Mouthwashing unfolds in a non-linear fashion, oscillating between timelines before and after the Tulpar spacecraft crash. The story is told from the perspectives of Curly and Jimmy, both of whom experience hallucinations that add a layer of complexity and ambiguity to the narration. It’s essential to immerse yourself in the interactions and events to grasp the complete narrative and its intricacies.

Additional Tips

– Story Understanding: Engage with character dialogues and interactions. Take notes if necessary to create a timeline of events that aid in understanding the story’s nuances.
– Exploration: Each area of the game is packed with details that contribute toward the atmosphere and storytelling. Actively searching for items and interacting with the environment is vital in your quest for completion.

Optional Content

– Hallucinations and Interactions: Interact with any hallucinations you encounter and engage with the peculiar elements of your surroundings to delve deeper into character psychological states.
– Environmental Clues: Gather clues scattered throughout the game that flesh out character backstories and motivations.

Final Notes

Achieving full completion in Mouthwashing calls for meticulousness and patience. Focus on all interactions, collect crucial items, and explore every nook and cranny of the game environment. Be aware that various endings hinge on specific actions, particularly those involving interactions with Swansea or choices made by Jimmy. By following this guide and maintaining an exploratory mindset, you will be well on your way to 100% completion in Mouthwashing. Good luck!