This seems like the most appropriate place to post about bullet direction...
I set the angle of the Bullet to 180 degrees but its behaviour wasn't remotely as expected.
Whether or not the bullets are fired at 180 degrees seems to depend on how rapidly I press the shoot key (space-bar). E.g - if I press the space bar only after the previous bullet has disappeared from the screen then the bullets are fired at approximately 45 degrees, but if I press fire again before the bullet is completely off screen then it fires out at approximately 135 degrees and will only fire at 180 degrees if the space-bar is pressed rapidly within short duration between presses.
Does anyone have any idea as to why this could have happened?