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
Win 200 Matches
Use 20 Different Awesome Attacks
Beat Tournament of Legends with 12 Characters
Play 12 Different Levels
Win 100 Matches
Beat Tournament of Legends with 6 Characters
Win 50 Matches
Win 10 Timed Matches
Win 5 King of Kung Fu Matches
Win 5 All You Can Eat Matches
Win 10 Matches in Team Play
Win 10 Stock Matches
Play 8 Different Levels
Play 4 Different Levels
Complete all Tutorial Lessons
Use an Awesome Attack
Play Practice
Check out a Fighter in the Character Bio
Win an Online Match