Here is the full list of all 11 Real Boxing™ achievements.
Win your first fight.
Win your first fight by KO.
Win a fight without getting hit.
Complete the tutorial.
Win the Roosters' Tournament belt.
Win the Night of the Champions belt.
Win the Boxing Legends belt.
Fully train your character.
Win 50 fights.
Perform 100 counterattacks.
Win all belts without getting knocked down once in the process.