Eternal Champions Secret.
There is a secret code that on the Sega screen, before it mentions title, changes the opening character's animation to remove his glasses and do a tough guy pose.
- Code: c, down, up, b, b, b, a, c, c, c, b, a
As soon as the word Sega pops up immediately start this code and keep inputting until after he gets done tapping his arms. I mention this because it makes it easier to hit the right timing to do this as it has a very short window of opportunity. Also the buttons described may not match exactly with your keyboard or controller as they match up to whatever button you selected to be assigned to them in input configuration.