Silent Forest: Zone 2
Red Star Ring 1: While being attacked by falling enemies near the beginning, look for a set of raised platforms above a robot that's throwing bombs. At the end, you'll find a Red Star Ring.
Red Star Ring 2: The second is beneath the path of the first section. Wait for one of the falling enemies to break through the floor, then grab it.
Red Star Ring 3: The third is impossible to miss, on a platform in the open immediately after you need to hop across three spiral-shaped bushes.
Red Star Ring 4: This one is located on a very high platform immediately following a short sequence in which you must use the musical note power-up to cross a gap. You'll need to get a boost by attacking the bouncing enemy directly beneath it.
Red Star Ring 5: You'll find the last one in a narrow opening on an electrified platform not long after the previous Red Star Ring.