On the left side of the game window is a vertical display showing the words "BONUS" and + 2, + 4 and +10. To enter the free spin, the player needs to illuminate the least characters in the cascade sequence. If you don't do this, the display will be reset again before the next rotation.
A winning cascading or reward scatter will illuminate a character for each character that appears. For example, hitting a winning combination and a bonus dispersion on the initial cascade will illuminate the characters B and O on the reward panel. Once the entire word "BONUS" is illuminated in sequence, it will trigger an initial 10 free spins with a x1 starting winning multiple. When hitting six, seven or eight consecutive winning cascades or bonus symbols in a single rotation sequence, the extra + 2, + 4 and +10 free spins for a total of 26 free spins.