Knytt Stories - Pest Control Beta Playthrough #2 Part 1

In this playthrough, I was aiming to get the six coin ending. So to do that, I skipped both powerups. Interesting idea, but I don't understand how you're supposed to get past the spikes like this. I noticed that you can slip underneath their tips, but that only seems to work at random. So this particular playthrough is on hold for now.
Also noticed a minor bug. If you try to leave after the first job without accepting full payment, then collect all the coins and head back to the door, the sign telling you not to leave any coins behind will still appear.