Boston-bred New Kids On the Block get a bit sentimental on this five-song EP, with the synth-spangled title track shouting out the boy band’s devotees and the “99 Luftballons”-echoing “Still Sounds Good” saluting the decade that birthed the quintet. The ‘80s babies flaunt their 21st-century bona fides on “One More Night,” which uses the sparse textures of EDM-pop as a springboard for their silky harmonies, and the winking “Hard (Not Luvin U),” a lite-funk bounce that puts Jordan Knight’s falsetto up front.