Here is the full list of all 22 Say No! More achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Let someone pay for parking tickets.
Deliver Grahams letter.
Subscribe to the Coaches Channel.
Say "No!" 99999 times.
Say "No!" 9999 times.
Say "No!" 999 times.
Complete the story.
Complete chapter 7.
Complete chapter 6.
Become the Staring Contest Champion!
Complete chapter 5.
Make fun of 10 workers.
Complete chapter 4.
Complete chapter 3.
Complete chapter 2.
Win a Staring Contest Fight!
End ten encounters without saying No.
Complete chapter 1.
Play Alex' new video game.
Don't hurt the janitor imp!
Say "No!" 99 times.
Design your first character.