Oh...I didn't download the manual booklet, so I...right.
Fair point, but there are still enemies that move into you by the time they are on screen, making parts of the game unfair. As for the double backing, the problem with that is it becomes unpredictable which further disrupts flow when doing good on a level.
Side note: Despite being hell, it was indeed "fun" in a hard to describe way. Even if there are things I don't like about this: thanks for making it and giving people the chance to enjoy your creation.