Here is the full list of all 48 A Forgetful Loop achievements.
Complete the Gamejam-inspired levels
Complete the last group of levels
Fix every level
Fix the machine for the last time
Assign a character to 6 different nodes in one loop, and not fix any of them
Switch a Switch with 2 connections 5 times in one loop
Fix 2 Briefcases in one loop
Fix a Briefcase in the last 5 seconds
Complete the sixth group of levels
Fix a node with 4 engineers
Complete the fifth group of levels
Switch a Switch 5 times in one loop
Skip 40 seconds in one loop
Assign at least 5 characters to a Fuse with 1 slot in one loop
Fix a level with a Hazard node by only fixing Hazards with Leads
Complete the fourth group of levels
Complete the second group of levels
Fix a node with 4 scientists
Have every character assigned to nodes at the same time in a loop
Assign a Student to a Spinner at the start of a loop, and leave them there until it resets
Fix a Goal node with just Students
Fix a level with a specialised Hazard node without matching the departments
Skip 5 minutes worth of time
Complete the third group of levels
Fix a level with 30 seconds or more on the clock
Spin 4 Spinners at the same time for half a loop
Fix a node with Isabel & Yolanda together
Fix a level with a Spinner without assigning Jennefer to any Spinners
Fix a node with Jennefer & Isabel together
Go an entire loop without assigning anyone
Assign a character to a Fuse node just before it breaks
Complete the first group of levels
Play through a group from Intro to Outro in one sitting
Fix 256 nodes
Fix a Time node for the first time
Fix a Goal node at the very last second
Fix a level without reassigning a character while they're fixing a node
Grab a character as they fly back to the department sheet
Start the machine
Read every story (Intros, Interludes, Outros & "The Story Before")
Experience 365 loops
Experience 999 loops
Have a character sick from Hazard nodes for five loops in a row
Have every character from a department sick from Hazard nodes at the same time
Fix a level without assigning any Students
Fix a level without assigning either Lead
Assign every role in a department to a node once in a loop
Complete every other Achievement