WOS 2-01 'bonus multiplier' not just a passive statistic

[Drew]

I was recently playing WOS 2-01 'Fire in the Sky' and having a very hard time finishing this very simple level until I noticed something interesting. When the stat called the 'bonus multiplier' was anywhere from 1 to 4, Deathclaw would only shoot 1 "icebolt" every time I hit the down arrow key to attack. But when the multiplier reached 5 (and above), Deathclaw suddenly began shooting 3 icebolts with every stroke of the down arrow key. I had previously thought that the bonus multiplier was only a passive, score-keeping stat, but I guess not. The difference in difficulty is huge, as it is virtually impossible to beat while the multiplier is less than 5, but it becomes very easy when it is 5 or more. Anyone else notice this?
Also, RCX, did you say that the three journal pages in this level are acquired by completing the mission objectives? When I checked the wanderers journals after completing the level, I didn't seem to notice any additional journals.