Here is the full list of all 48 Fatal Fight achievements.
Won a battle in "Weapon Round" without a single mistake
Slain 1000 enemies
Lost 5 battles
Defeated the first boss.
Killed 10 brawlers with ranged or thrown weapons
Won a fight with one hit remaining
Slaughtered 100 opponents with different melee weapons
Acquired your first secret skill
Won a battle in "Defender Round"
Completed the tutorial.
Killed three enemies in one second with your bare hands
Brutally murdered your opponent
Defeated the second boss
Defeated the third boss
Defeated the fourth boss
Defeated the fifth boss
Defeated the sixth boss
Defeated the seventh boss
Teared to pieces 500 opponents
Completed 10 battles undamaged and without single mistake
Completed 50 battles undamaged and without single mistake
Acquired ten secred martial skills
Acquired all secret martial skills
Devasted 100 opponents with combo attacks
Won a fight despite missing your opponents 20 times or more
Won a battle in "Thunderstorm Round" without a single mistake
Make 10 or more mistakes during the battle in "Thunderstorm Round" and win it
Won a battle in "Time Round" without a single mistake
Lost 100 battles
Restarted a mission 10 times
Return to game after 30 crushing defeats
Slain 15 enemies with one skill attack
Slain 10000 enemies
Slain 100000 enemies
Slain 500 enemies during single arena match
Slain 1000 enemies during single arena match
Slain 3000 enemies during single arena match
Slain 1000 enemies in single combat without taking damage
Use a single booster
Upgrade a single booster to max level
Upgrade all boosters to max level
Unlocked 12 apparel items
Use "Panda" costume to prevent damage 15 times
Make 100 earthquakes with your "Furious" costume
Kill all enemies on screen with your "Voodoo Doll" 25 times
Lose your "High Hair" 25 times
Use 300 secret skills in your "Witch" costume
Get 100 weapons with your "Chinese Sword" equipped