Here is the full list of all 22 Kung Fu Panda Showdown of Legendary Legends achievements.
KO 1000 Opponents
Win 5 Master of Inner Peace Matches
Beat Tournament of Legends with 20 Characters
Use 20 Different Awesome Attacks
Win 200 Matches
Beat Tournament of Legends with 12 Characters
Beat Tournament of Legends with 6 Characters
Win 100 Matches
Win 50 Matches
Play 12 Different Levels
Win 5 King of Kung Fu Matches
Win 5 All You Can Eat Matches
Win 10 Matches in Team Play
Win 10 Timed Matches
Win 10 Stock Matches
Win an Online Match
Play 8 Different Levels
Play 4 Different Levels
Check out a Fighter in the Character Bio
Play Practice
Complete all Tutorial Lessons
Use an Awesome Attack