I'm trying to collect all the achievements in Shadows Over Loathing. Which achievements are missable- i.e. it is possible to have a save state where the achievement cannot be earned without creating a new character?
A lot of them:
Fuel Reserves is only available in the prologue.
The following are related to cursed items. If these items are uncursed without doing the prerequisite for the achievement, they cannot be earned:
- Duality of Hat
- The Hot 100
- The Dark Side
The following are related to certain quests. If the quest is completed incorrectly, the achievement cannot be earned:
- A Victimless Crime
- The Prince of Tides
- Freaky Frogday
- Bad Dog(s)
- Jasper's Six
- A Friend of Ours
- Temporal Oopsie
Certain achievements require certain courses to be taken at SIT:
- Cleaning House (Requires Chemistry, Meta-Acoustics, or Spiders to unlock Hilbert House
- Your Neck Will Go On (Requires Chemistry)
- A Well-Rounded Education (Requires everything over multiple playthroughs)
All seven achievements related to a companion saving the world are missable- either by not recruiting that companion, by absorbing a monolith, or with too much shadow taint.
The collection achievements include missables in the prologue and elsewhere:
- The Gang's All Here
- Cat Fancy
- Sanitation Engineer
Certain achievements become impossible after initiating certain combats:
- No, Truce With the Fishies
- The Milk of Human Kindness
- Somebody Else's Problem
Finally, Hardcore Gamer requires 15 of each M-stat. There is no repeatable way to improve stats and many are limited or missable.