Here is the full list of all 19 The Hong Kong Massacre achievements.
All weapons and upgrades unlocked
Game completed
One hour in slowmotion
Second day completed
Died 250 times
1000 enemies killed
First boss completed
25 Doors destroyed
First weapon unlocked
Picked up 50 weapons
100 enemies killed
Completed a level on first try
Completed a level without slowmotion
First level completed
First enemy killed
Complete first day without dying
10 000 enemies killed
Complete the first and second day without dying
All challenges completed