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