Here is the full list of all 78 Knotwords achievements.
Get a 365 day streak in classic
Get a 365 day streak in twist
Complete 12 tricky puzzlebooks
Complete 12 standard puzzlebooks
Spell 100 ten-letter words
Spell 90 nine-letter words
Spell 10,000 words
Get a 31 day streak in classic
Get a 31 day streak in twist
Recovered a broken streak
Have spelled 'KNOT' and 'WORDS'
View the credits
Play puzzles for over 10 hours
Start a daily on the day and don't complete it
Get a 7 day streak in twist
Get a 7 day streak in classic
Complete a Twist Thursday puzzle in under 4 minutes
Complete a Classic Friday puzzle without hints
Complete a Classic Friday puzzle in under 5 minutes
Complete a Classic Thursday puzzle in under 4 minutes
Complete a Classic Wednesday puzzle
Complete a Classic Wednesday puzzle without hints
Complete a Classic Wednesday puzzle in under 3 minutes
Complete a Twist Tuesday puzzle in under 2 minutes
See each version of "good job" on the game over screen
Complete a Twist Tuesday puzzle
Complete a Twist Tuesday puzzle without hints
Complete a Twist Sunday puzzle
Complete a Twist Sunday puzzle without hints
Complete a Twist Sunday puzzle in under 20 minutes
No incorrect letters placed (on a Wednesday+ daily)
Complete a Classic Sunday puzzle
Complete a Classic Sunday puzzle without hints
Complete a Classic Sunday puzzle in under 20 minutes
Complete a tricky puzzlebook
Complete both puzzlebooks in the same month
Spell 80 eight-letter words
Complete a Classic Tuesday puzzle in under 2 minutes
Complete a Classic Tuesday puzzle
Complete a Classic Tuesday puzzle without hints
Spell 70 seven-letter words
Undo 100 times
Misspell 100 Words
Spell 1,000 words
Have spelled 'ARROW' and 'KNEE'
Complete a Classic Monday puzzle
Complete a Classic Monday puzzle without hints
Complete a Classic Monday puzzle in under 1 minute
Complete a Twist Monday puzzle without hints
Complete a Twist Monday puzzle in under 1 minute
Complete a Twist Monday puzzle
Complete a Twist Saturday puzzle
Complete a Twist Saturday puzzle without hints
Complete a Twist Saturday puzzle in under 10 minutes
Complete a Classic Saturday puzzle
Complete a Classic Saturday puzzle without hints
Complete a Classic Saturday puzzle in under 10 minutes
Complete a standard puzzlebook
Complete a puzzlebook without using any hints
Spell 60 six-letter words
Complete a Twist Friday puzzle
Complete a Twist Friday puzzle without hints
Complete a Twist Friday puzzle in under 5 minutes
Complete a Classic Friday puzzle
Complete a daily within 10 minutes of it unlocking
Spell 40 four-letter words
Spell 50 five-letter words
Spell 30 three-letter words
Spell 100 words
Complete a Twist Wednesday puzzle
Complete a Twist Wednesday puzzle without hints
Complete a Twist Wednesday puzzle in under 3 minutes
Complete a Twist Thursday puzzle
Complete a Twist Thursday puzzle without hints
Complete a Classic Thursday puzzle without hints
Complete a Classic Thursday puzzle
Play a daily from before the launch of the game