Overall is a slang term borrowed directly from English, famously used in video games to describe a character's total skill level. It's a perfect example of the Spanglish you'll often hear in modern Latin music.
In the lyric "Contigo me sube el overall" (With you, my overall rating goes up), Bad Bunny cleverly expresses that his partner makes him a better person. She boosts his confidence, status, and sense of self-worth, as if he's leveling up in a game.
Get ready for a super confident, possessive love song from Puerto Rican superstar Bad Bunny. The whole point of "Mía" is him telling his partner to make it clear to everyone that she's taken. He sees how other guys look at her, saying, "Todos están pendiente a ti / Pero tú puesta pa' mí" (Everyone is watching you / But you're for me). He's not shy about it at all, demanding she "Dile que tú eres mía, mía" (Tell them you're mine, mine).
He mixes romantic lines like "Bebé, yo soy fan de tu caminar" (Baby, I'm a fan of the way you walk) with some pretty intense claims. He tells her to warn off other guys, even on social media: "Dile a estos bobos que dejen de darte like" (Tell these fools to stop liking your stuff). He even makes a tough-guy threat, saying he'll scare them off with a gun. It's a mix of total devotion and serious jealousy, all wrapped up in a smooth reggaeton beat.