That's a pretty fun game. Simple controls, simple concept (harder than it sounds) and fits the theme well. I love that it's in 2D too. Temptation to do that in 3D would be huge, but it probably wouldn't work as well.
I've always enjoyed setup-and-run physics games, and this one is no exception. I like how you can sort of pick a parcel up off the running truck and use it to nanny the other parcels back into line! Only problem I could see was that the blue zone goes past so fast. Could have done with a limited slow-motion ability or something along those lines. Messy physics and slow motion are natural partners.