'Angry Birds Space HD' soars into orbit

The "Angry Birds" franchise is one of the App Store's biggest success stories. When it debuted almost two and a half years ago, its developers hit on a potent formula for casual gaming profits. Make it colorful, make it work nicely with a touchscreen, and make it really easy to figure out. Then throw in a satisfying element of property destruction, set the stage with a broad-strokes plot that's really very dark if you think about it too much, and you have your mega-million-earning game. Of course, there's also the work that has to go into marketing it and keeping it on top of the App Store charts. And the game can't be allowed to grow stale, either. Rovio has become very adept at making what you might call "semi-sequels." Sometimes new levels are added to a game for free. In-app purchases add new dimensions to the existing version. And every once in a while, a completely new version, like "Angry Birds Rio," is added to the lineup. But even with "Angry Birds Rio," the game's basic framework didn't change. Players got a new bird or two to launch at the porcine oligarchy, and the carnival backgrounds were a change of pace. But the basic song remained the same -- launch bird from point A and hit pig at point B. And so it goes for "Angry Birds Space HD." But one factor pumps new life into the franchise: gravity. Gravity Always Wins The story, as always, involves green pigs stealing the birds' precious eggs, thus enraging them to the point of mutually assured destruction. The birds fling their bodies face-first into the pigs' battlements, burying their tormentors and often themselves under piles of debris, sometimes exploding in the process. Since this is all happening in space, the birds are dressed in the finest of cheesy sci-fi regalia. And their familiar chattering has been replaced with something a little more other-worldly sounding. The pigs, however, remain roughly the same as before, and they build their fortifications with the same materials, save for an odd piece of rebar or two. Gravity is where things get interesting. No longer are you playing on a flat surface, flinging birds over land where everything climbs and falls exactly as you would expect on Earth's surface. For example, you might need to hit a pig stationed on the far side of a planetoid. There's also a planetoid or two in between his home and your slingshot. Each has its own gravitational pull. So you're going to have to aim your bird to swing around this orbit, fly off into that, make two or three revolutions around the target planetoid, avoid rocks and chunks of debris, and then crash down directly onto the porker's bunker. Of course, you won't need an advanced physics degree to plot your firing strategy. It's very possible all of the game's gravity concepts are incredibly simplified and unscientific. But if you want to argue science in regard to a game like this, we should probably start with the fact that if you took birds and pigs into space without giving them any kind of protective suits, you wouldn't have much of a game at all. Since aiming is a little more complicated in "Angry Birds Space," you get a little assistance each time you pull a new bird back. You'll see a dotted line that plots the first few yards of your throw from your given position, taking into account whatever pull of gravity you might encounter along the way. And what's an "Angry Birds" game without another angry bird? This one features an ice bird whose talent is to freeze whatever surface it crashes into, leaving it as fragile as glass for the next barrage. Bottom Line Fans of the "Angry Birds" series will find a nice mix of the familiar and the new with "Angry Birds Space HD." It's the same concept, of course -- those birds are too maniacally fixated on killing pigs to have any time for other pursuits. But this doesn't play like a bunch of add-on levels or swapped-out backgrounds. It's a game with a new element of gravity, and Rovio will no doubt squeeze dozens, if not hundreds, of new levels into it as time goes by.