There are two turbo modes that can be accessed by holding down certain buttons on a second controller before the game starts. The first will change the intro music and part of the title will blink between black and pink. The second will change the intro music as well and part of the title will blink between black, pink, and white.

Turbo Mode 1: Hold the L or R button before starting the game.
Turbo Mode 2: Hold the L and R buttons before starting the game.

These may both be a reference to the title screen font colors used in Street Fighter II Turbo: Hyper Fighting.