Here is the full list of all 11 Paddle Up achievements.
Beat bullseye level 1.
Defeat the master AI in a match.
Defeat the skilled AI in a match.
Defeat the casual AI in a match.
Beat all 6 levels of bullseye.
Beat anyone in an online match.
Score perfect in at least 1 bullseye level.
Beat level 4 of bullseye.
Beat the first level of "Beer" Pong.
Beer level 4 of "Beer" Pong.
Score perfect in at least 1 "beer" pong level.