Zimzalabim is such an upbeat optimistic song about chasing your dreams. The zimzalabim chant is catch too. it only sounds bad in the part before the bridge with that weird buzzing music and after the bridge it's just nanananana. i think SM expected to do it well as they had the whole mob dance to Zimzalabim when red velvet don't even post normal dance practice. SM wanted it to be a hype song that would play in stadiums.
On the other hand "really bad boy" is just continuous high pitched singing without any break which makes it so hard to listen and annoying even though the music is good.
