This pops when you do all other achievements.
For a fast and full Achievements guide check the link below:
Timestamps:
00:00 Intro
00:42 Gameplay
01:23 Empty Your Cup Achievement
01:54 Gameplay
02:02 Surfing the Radio Waves Achievement
02:39 Glow Up Achievement
03:04 Gameplay
03:29 Hopping the Turnstile Achievement
03:52 Gameplay
05:31 Wood War Achievement
05:54 Gameplay
06:14 Siren Song Achievement
06:42 Oh Buoy! Achievement
07:14 Gameplay
07:47 Bubbling Over Achievement
08:06 Fan Service Achievement
08:20 Gameplay
08:52 Knock ‘Em Down Achievement
09:06 Gameplay
10:17 Flipper Friend Achievement
10:30 Gameplay
13:49 Sink and Swim Achievement
14:30 Gameplay
15:03 Mirror, Mirror… Achievement
15:37 Gameplay
15:53 Home Sweet Home, All Done! Achievements + Outro