Hmm, the gravity scale was at 0 for some reason (not the default), but that had no effect. I tried leaving that at 0 and changing the initial/max speed to be higher, no effect, adjust the velocity as well as the initial/max speed also had no effect and setting the velocity high in the X value (to ~9000) still, has no effect.
I also tried a similar value for velocity in the other axes, but this also had no effect.