As you progress, more items are added to build more-complex vehicles, from the simple two-wheeled contraptions in the beginning to multiple part machines. Later you'll build flying machines and navigate through caves and other obstacles, where your construction means the difference between getting the map piece and a respectable star score or not making it to the end at all.
Bad Piggies comes with three areas with approximately 45 levels each. There are also special challenges at every fifth level with unique requirements that will take more thought and experimenting to accomplish. What it all adds up to is another great game from Rovio, but it's much more challenging than the Angry Birds variations you're used to.
One surprising drawback to Bad Piggies is that it is not yet ready for iPhone 5. Like many games that haven't been upgraded for the wider screen, Bad Piggies has black spaces on each side, which is perhaps because the game was released soon after the new iPhone, but I think it really should have been ready for the new device from the start.
Also, with the new, more-complex game mechanic, Bad Piggies will not be as accessible to all ages like Angry Birds was. Rovio seems to be trying to make a game that will appeal to a large part of its already huge fan base, while trying to draw in more-serious gamers at the same time. Time will tell if it's able to pull it off, but make no mistake that this game is not as easy to figure out as any game the company has made before.
Still, Bad Piggies is a unique and interesting new game type that will appeal to both casual and serious puzzle gaming fans. With several levels to start off (and more on the way), excellent physics, and characters you can recognize from the earlier games, Bad Piggies is easy to recommend to people looking for a new challenge. Unfortunately, the game will probably only make the birds angrier.