In the "FIRST To Press The Button Challenge (Paunahan!)" video by Ranz and Niana, the siblings compete in a fun and fast-paced game where they must quickly press a button to win different challenges. Each round features various tasks or questions, and the first person to press the button gets to answer or perform the challenge. The video is filled with excitement, laughter, and sibling rivalry as they race to outdo each other. It's an entertaining challenge that keeps viewers engaged with its lighthearted competition and fun twists!