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