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