Here is the full list of all 20 The Hong Kong Massacre trophies - there are 5 bronze, 6 silver, 8 gold and 1 platinum.
All trophies unlocked
10 000 enemeis killed
All challenges completed on normal difficulty
All weapons and upgrades unlocked on normal difficulty
250 deaths
Game completed on normal difficulty
One hour in slowmotion
1000 enemies killed
25 Doors destroyed
Complete the first and second day without dying on normal difficulty
Second day completed
Complete first day without dying on normal difficulty
Completed a level on first try
First Boss completed
Picked up 50 weapons
100 enemies killed
First weapon unlocked
Completed a level without slowmotion
First level completed
First enemy killed