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