Here's a game I never saw coming: a driving title where you're supposed to drive like a vigilant hypermiler. Yep, that's exactly what the unholy union of Volkswagen and Fish Labs turned out with the Volkswagen Think Blue Challenge, a game where the goal is make every last drop of your fuel count. Here's something even crazier - it's quite entertaining.

While the premise sounds silly, the challenge is not. It's one thing to delude yourself about your eco-friendly driving abilities when you're on the road. When you've got just a small amount of fuel to make it through checkpoints, though, it becomes a...gasp...game.

In Think Blue, you start the game with a small amount of gas and drive from one checkpoint to the next, getting a small amount of extra fuel for every one you clear. You complete checkpoints by correctly answering a question about efficient driving. Don't worry, if you drive even a little bit, you probably know the answers.

Once you've finished all checkpoints, you then begin driving your car on the open road. Make sure you apply every fuel efficiency trick up your sleeve, from coasting down slopes to managing your throttle to taking turns intelligently, allowing the vehicle to cover as much ground as possible before your tank goes empty. The game does help you out, suggesting how to maximize whatever's in your tank, going so far as to explain why each technique works. You will eventually run out of gas and when you do, the game submits how far you've driven to the online leaderboards, where you can see how you fare among the mass of iPhone-toting hypermilers around the world.

Volkswagen Think Blue Challenge is built upon the same engine as Fish Labs' Rally Master Pro 3D, so the graphics and the mechanics are all awesome. While it's not going to be the most exciting game in your library, it is quite addicting, especially once you see how far the top performers have gotten. Plus, you might even learn a new thing or two about technical driving. You can download the game for free from the App Store.