RED ALERT: Bad Piggies [Free / Free (HD)] is Apple's App of The Week. As such, it's now available at the price of free instead of not-free (or 99¢, if you're keeping track at home).

You'll want to grab this one, too. It's an imaginative puzzle platform game that tasks users with building fantastical machines and navigating them through a physics-enabled world to an end goal. The catch is that there's tons of obstacles around, and machines need the right parts and the construction to get past them.

We gave Bad Piggies a big old five stars, which is a really good score. It's a treat to play. The mechanics are solid and the level design does a fantastic job of enticing you to build increasingly whackier contraptions. Give our review a read if you'd like -- or just download the game since it's, you know, free.