Here is the full list of all 9 Handshakes achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Complete 10 puzzles.
Complete 20 puzzles.
All puzzles completed.
Complete Level 10 without cutting an arm.
Complete Level 18 without cutting an arm.
Complete a Speedrun. (start from options menu)
Complete Level 11 by cutting an arm and shaking a Hand simultaniously.
Shake a Hand
Complete a Speedrun in under 600 seconds. (start from options menu)