I have been playing Metroid games since the very first. There are instances where you don't have any visual information about the fact that a bloc is breakable. You are meant to explore and try things.No, this isn't standard metroid game design. They don't put a series of destructable blocks above and below you but in order to progress you have to shoot the floor that has no visual cues to shoot. Castlevania SOTN never had this problem, nor did Cave Story, nor did Axiom Verge nor did Super metroid.