There's a lot of steps you have to do to initiate this. How did Breakout just appear? Below is how you start it. Unless there is a special ROM, seems weird you'd just stumble across it.
1 start a game
2 enter the code using flippers B,1R,2L,1R,4L,1R,8L,2R
3 begin paying the game normally
4 get the holideck mode (right ramp twice then right orbit)
5 when prompted for holideck choose 25k, hold gun trigger down and press right flipper button
6 instead of Rikers poker, breakout starts. You get 5 balls in breakout shown down right side of dmd