Wait, I figured it out - you're supposed to fire the rodent straight through the center of the earth and out the other side. Ah, it makes perfect sense now. I think.
Well, it took me absolutely ages and nearly killed my computer from the slowdown and I died about 7 kills later, but I finally scored the Medium Badge. Hooray for me!
And the winner for failing to read instructions properly is me. I was already to rate this game a 1 for the difficulty in aiming the darn bow, until I finally realized you could set it to Auto Aim -_-
Watching this gigantic squishy cat as it is sandwiched between two gears is simultaneously the most awesome and most disturbing sight I've seen so far this week.