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