“Sappy” is Red Velvet at their very best as they bounce along the brassy electro-pop track. It switches up momentum every few moments while vacillating between the boisterous chants of the chorus and the melodic verses that explode with Red Velvet’s powerful vocals. It’s snappy just as much as sappy, and a fun way to start off 2019.
Lyrically, the song is about Red Velvet telling the “Sappy” boy to pick between two romantic interests, and that it's not a game. Though the music video doesn’t reflect the decision, it's a fun-filled time as the five members of Red Velvet interact with a variety of sets that draw on video games for some inspiration. Throughout, they spend their time playing around with foam and washing cars while Irene tallies up a total of sorts, perhaps a measurement of love. With the colorful, industrial setting and the peppy, hand-oriented moves of the choreography, it's a bit of a throwback to the group's "Dumb Dumb" days but with a bit of a sharper, more mature edge.