Oh my god, the childhood memories! When I got my first iPad courtesy of my mother when I was at least 7 (back in 2010 or 2011, I can't exactly pinpoint the exact year,) lo and behold, Soosiz was one of the games there. I decided to play it, and the main menu screen/level select music stuck to me.
The whimsical flute tittered in the background as those little creatures waddled about across the screen. When I played the first level, the game greeted me with ragtime-esque piano music set to a similar melody as that joyful flute-playing mentioned earlier. When I finished that level, a mini orchestra with bassoons, bells and a piano congratulated me with a playful rendition of 'Up On The House Top' as the main three mini creatures I collected throughout the level hopped with glee as if they were proud. The quirky ragtime piano music didn't stop there, as different melodies containing the playful piano varied from level to level, occasionally a little more negative tune with stringed instruments found in some levels with those rolling Whomp-faced balls.
The music stuck to me, even after all these years of not playing.