Here is the full list of all 19 Happy Pong achievements.
Change the shape of the screen.
Reach a Happy Face combo of 120.
Complete the tutorial.
Discover the Easter eggs.
Survive the invasion.
Finish a game of Happy Pong with no customization effects turned on.
Finish a game of Happy Pong with all customization effects turned on.
Attain a high score that exceeds 20000000000 points in "Ballzooka" mode.
Attain a high score that exceeds 20000000000 points in "Weaponizer Extreme" mode.
Attain a high score that exceeds 20000000000 points in "Classic Pong" mode.
Attain a high score that exceeds 5000000000 points in "Credits DevBlaster" mode.
Start a game with the wondrous x60 base multiplier.
Finish a game of Happy Pong with only the Original customization effect turned on.
Reach level 30.
Attain a multiplier of 500 or more.
Attain maximum menu illegibility. Helpful note: Illegibility increases when a game ends or you quit a game, but not when you restart one. Illegibility resets when the application closes.
Finish 10 games of Happy Pong.
Finish 100 games of Happy Pong.
Attain a lifetime score of 500000000000 or more points.