Here's an interesting give-away type keychain. It's a Rubik's Cube (but small) It likely works just like a normal size one, as you turn the layers of blocks to try to match the sides. It's likely that the other sides of the cube have different Sonic Battle related icons. What do the other sides look like? This side has the Japanese logo & Rubik's logo. Judging by the size of the ring, this isn't very big at all. This was a booth prize type freebie at Tokyo Game Show in 2003. It is uncommon. (you can't read what's under the Rubik logo as the original photo was blurred)