K.I.S.S: Keep it simple stupid. This game is a poster child for that philosophy and it succeeds nicely.
I enjoy the simple goodness of flash games like Funky Truck. With Smuggler's Run I can groove on the the driving physics and simple techno and assuage my gaming soul as an antidote from playing something far more frustrating or complex. Yes, the police vehicles are unabashedly insane, they drop out of the sky and flit around your vehicle like flies trying to mate with you, but if you take it in stride and laugh at it for what it is you'll have a blast.
This combined with the fact that you can pick up this game for next to nothing makes it a great investment in my neat little book. It represents some of the best four bucks I've ever spent. Do yourself a favor.