Glinty Circular Disc

The Glinty Circular Disc is a treasure in. It is actually a Japanese disc of  for the Nintendo GameCube.

Collecting the treasure
The treasure is located on the final sublevel of the Engulfed Castle and is dropped by the Waterwraith upon defeat.

Trivia

 * GameCube discs as treasures were originally planned for, as evidenced by four unused models. However, Wave Race: Blue Storm was not among these four.
 * Coincidentally, Prima Games once published a 4-in-one strategy guide which included both the guides for and Wave Race: Blue Storm.
 * This treasure's name can be abbreviated to "GC Disc", as in "GameCube Disc". This is likely intentional, as "GC" is present in the Japanese, Korean, and both Chinese names, and most other languages are direct translations of the Japanese name minus the "GC".