Here is the full list of all 23 Lethal League achievements.
Reach a ball speed of a hundred thousand
Reach a ball speed of one million
Play one thousand matches
Reach level 20
Hit three players in a row
Play five hundred matches
Reach level 10
Beat the challenge mode with every character
Rally the ball back and forth for at least ten times
Beat the challenge mode with Raptor
Reach a ball speed of one thousand
Beat the challenge mode with Latch
Beat challenge mode with Candyman
Beat the challenge mode with Switch
Play a hundred matches
Beat the challenge mode without using any continues
Beat the challenge mode with Dice
Get hit by your own ball
Beat the challenge mode with Sonata
Bunt the ball at 1000 speed or above
Reach a ball speed of two hundred fifty
Reach a ball speed of one hundred
Hit two players in a row