Here is the full list of all 28 Manual Samuel achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Didn't fall down the stairs
Complete Level 2
Complete Level 1
Complete Level 3
Complete Level 4
Complete Level 5
Complete Level 6
Complete Level 7
Complete Level 8
Drink two cups of coffee
Completed Sams house only breathing in 15 times
Drove 150 km per hour
Spoke perfectly
Kill every robot
Complete Story Mode Single Player
Complete Story Mode Co-Op
Get bronze or higher on every time trial
Get silver or higher on every time trial
Get gold on every time trial
Unlock all the Achievements in Manual Samuel
Skipped a cinematic
Went to work without shoes
Tip Tony
Blow up Tony
Made no stains on yourself
Blink 2000 times
Didn't skip any cinematics
Found every hashtag