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