Here is the full list of all 12 Kings of Kung Fu achievements.
Win a round with less than 10% health
Win a round without losing any health
Win a battle in either: Story Mode or Versus Mode
Complete the Story Mode with one character
Complete the Story Mode with all characters
Complete the Story Mode in max difficulty level
Complete the Story Mode without using any continue
Complete the Story Mode without losing any round
10x hit combo
Win 10 consecutive games in Versus Mode
Win 20 consecutive games in Versus Mode
Win 100 consecutive games in Versus Mode