Gotta go back up, use the metal boots to hook onto the quarter and then use the grappling hook to the black bar on the right side of the long green bar.
So I went back up and grabbed the quarter. I hooked onto the metal gear to the right of the green pole and I went through it. Why did it let me go through it? Am I missing a fundamental aspect of the game?
No, you're not dumb - it took me a bit to figure that one out, too. I think the best thing to do with this game is always try different things, think outside the box.
By the way, there's a memory chip under that red bar on the floor, too...
So I went back up and grabbed the quarter. I hooked onto the metal gear to the right of the green pole and I went through it. Why did it let me go through it? Am I missing a fundamental aspect of the game?