Oropel literally translates to "tinsel" or "gold leaf." It refers to something that looks shiny and valuable on the surface but is actually cheap and worthless underneath.
In the song, the singer uses oropel to describe how he can turn something seemingly important into something trivial if he's not valued. He sings, "Juego yo y lo vuelvo oropel si yo no soy el rey del Castillo" (I play and turn it into tinsel if I'm not the king of the castle), implying that if he's not treated as the most important person, he'll expose the superficiality of the relationship.
Have you ever felt like you gave someone everything, only for them to completely change on you? That's exactly what Peter Manjarrés is singing about in "Así No Va" [That's Not How It Goes]. He's telling his partner that if she's tired of him, she should just leave because he's not going to live through a "calvario" [calvary].
He remembers planning a future with her, saying, "Pinté mi vejez junto a ti desde que nos vimos" [I pictured my old age with you since we met]. But now, he feels like she's taken his "torre de Eiffel y la echaste abajo" [Eiffel Tower and knocked it down]. He's not denying she's a good person, even saying she deserves the best, but he's firm: "Yo no estoy dispuesto a que me pase por encima" [I'm not willing to let you walk all over me]. He even built her up, saying, "Yo te hice orgulloso el pedestal con el que brillas" [I proudly made you the pedestal you shine with], and he thinks that might have actually hurt her. He's confused, asking, "Por Dios a dónde está la que traté en otros años" [For God's sake, where is the woman I treated in other years?]. He's not going to be a clown for her, making it clear, "Yo para payaso no sirvo" [I'm no good as a clown]. It's a powerful song about knowing your worth and not letting someone disrespect you.