I'm a firm believer that Rovio Mobile has a high-ceilinged vault in the back of its office filled with mounds of cash and coins from the billions and billions of Angry Birds [$.99 / Lite / HD] purchases. I reckon it'll need to build a new money vault rather soon as a direct result of the game's latest update, which adds 15 new themed levels and the long-awaited Mighty Eagle, a bit of paid DLC that adds a new, pig-annihilating bird to the Angry Birds roster.

Let's back up a second. Update 1.5 adds a Wild Western-themed chapter called "Ham 'Em High." A total of 15 new levels are introduced, none of which feature anything stunningly new from a design perspective aside from cowboy hats and sombreros. It also adds a new Golden Egg "for y'all city slickers" to discover.

But the update also adds the Mighty Eagle, a one-time, $.99 bird purchase. The Eagle is basically the Angry Birds version of a nuclear bomb. To use it, you slingshot a can of sardines into the environment. When the can stops, the Eagle swoops down and banks off the geometry, causing the physics to react from the aftershock. This clears the level of all pigs and then you can progress.

The thing to note here is that the Eagle can only be used once an hour if you're using it in levels that you haven't completed. But if you use it in levels that you have completed, you can go to town as often as you like, with no hour cooldown.

There's a cool meta-game with the Eagle, too. After you clear a level, a destruction indicator pops up and reports the percentage of the level you destroyed. The goal here is to to completely wreck a level. Once you've got 100 percent, you get a small feather next to the stars on the level select screen, luring completionists in to replaying the whole game again with the Eagle.

It's hard for me to tell if the Mighty Eagle disrupts the game's balance. I think it's more of a creative level-skip than anything else, considering you don't get the same sort of satisfaction from pounding the Eagle "Win" button. But these new levels are the only ones I've yet to beat, so my frame of reference is bad. The hour between skips seems like a good compromise between letting you skip forward if you're stuck but preventing you from just skipping through the entire game.

All in all, this is another good update from Rovio, and the new Mighty Eagle destruction gauge makes the new IAP a must-have for every Angry Birds lover.

Earlier this month we posted a brief teaser video from developer Mobigame for their newest iOS title called Perfect Cell [$5.99]. The video didn't explain much in the way of gameplay, nothing at all in fact, and we were left scratching our heads wondering exactly what Perfect Cell was all about. Now that the game has actually been released I've spent a good deal of time with it, and it has turned out to be unlike anything I could have imagined. It's sort of a mishmash of genres, with elements of action, platforming, stealth, and puzzle. These end up working really well together, and coupled with intuitive controls and a beautiful graphics engine, Perfect Cell is a good time from beginning to end.

The story of Perfect Cell starts as an asteroid crash lands to Earth in the not too distant future. Humans discover a form of life in the asteroid that is advancing at an incredible rate. They keep this life form in a research facility deep below the sea in order to study it, but after some time the alien grows into a sentient being who doesn't fancy being held in captivity. It then becomes your job to control this squid-like alien as you negotiate intricate levels full of puzzle-like traps, enemies, and hidden passages in an effort to break free.

The look of Perfect Cell employs a 2.5D perspective, similar to Shadow Complex, with fully 3D backgrounds but action that takes place on a single side-scrolling 2D plane. The lighting effects in the game look fantastic, as do the style of the characters and environments. The underwater facility almost gives off a James Bond-like vibe with giant computer panels and scientists in lab coats spread throughout. Shortly after the game begins soldiers start to infiltrate the facility, and don't seem to take kindly to the scientists, and certainly don't take kindly to the alien being.

You control your alien in Perfect Cell by simply touching and dragging to move, or touching and holding to call the alien to that position. Quickly swiping the screen performs a dashing attack that can kill enemies and bash through certain structures to find hidden areas. Later in the game a super dash attack is introduced, where you can charge up and draw a line that the alien will rapidly follow, killing anything along the path. Also, as you progress you'll run across a couple of your alien buddies which absorb into you, making you larger and stronger. You can then use a pinching apart gesture to split yourself into two or three separate beings, controlling each individually to conquer tasks that require being in multiple places at the same time.

Perfect Cell contains 35 levels to play through, and in reality it will only take several hours to complete them when destroying anything in your path. The real genius to this game comes from not killing people. There is a stealth element to the game, and its very possible to complete every level without killing a single person. This is where serious strategy comes into play. Upon seeing you guards will become alerted in a very Metal Gear Solid kind of way, minus the exclamation point above their head, and will seek you out for a short time before becoming bored and going back to normal patrol.

It would be easy to just dash attack the life out of these guards, but when trying to complete the game without killing anyone you'll need to take advantage of hiding spots and your ability to cloak yourself by staying still. Taking this pacifist's route through the game is really challenging, and practically turns Perfect Cell into two completely different games depending on how you play.

The only real problems I had while playing came from the controls. They're very intuitive and touch screen friendly, but lack precision at times when you need it. Also the dash attack isn't always reliable, and when you're counting on pulling one off during the split second when a guard's back is turned it can be detrimental when the move doesn't come through. These problems are minor, however, and for the most part there's nothing that will hamper you from progressing and enjoying the game.

There's really nothing like Perfect Cell on the iOS platform, and it offers some refreshing gameplay and fetching visuals. It doesn't take too long to whiz through the game when you're killing everything you see, but sparing lives and utilizing stealth offers a real challenge that will keep you busy for a while. There is also Game Center integration for achievements and high score tracking. Fans of games like Splinter Cell or Metal Gear Solid will find similar gameplay in Perfect Cell, along with the exploration and puzzle solving of the Metroid series.

Perfect Cell blends all these different elements together seamlessly, and creates an experience that feels like its own. Players in our forums have been enjoying this one too, and Perfect Cell is recommended if you enjoy any of these previously mentioned influences or are just looking for a new unique gaming experience.

If you're in the mood for some Tilt To Live [$2.99 / Lite, HD], now is a better time than most to boot up the title. Developer One Man Left Studios has pushed out a new update to the game, adding in a new mode and a new weapon via an in-game $.99 purchase.

The update, which is available on the game's main menu, has been lovingly dubbed "Viva la Turret," and as it implies, it gives you access to a mounted chaingun-like weapon. The weapon, "The Perforator," is exclusive to this new mode, which is also called "Viva la Turret."

The point of Viva la Turret is to grab points, of course, and the easiest way to do so is by collecting "The Perforator" power-ups that spawn on the map. Whenever you get access, you'll be assault by a stream of projectiles from all angles. The key here is to use it without getting smacked, and then to snag all the sweet blue leftovers from victims for crazy points multipliers. Here's a video of it in action:

Viva la Turret seems cool and should provide a nice change of pace opportunity. That's not to say Tilt To Live every really gets old, but hey, something new to do with a game you love, right? I'll note here that this update is currently only available for the iPhone and iPod Touch versions of the shooter. An HD version of the update is in the works, however.

Tilt to Live, if you didn't catch my drift earlier, is a fantastic game. I don't know if there's anyone out who doesn't own it already, but if you don't, you'll probably love it. Here's some literature if you're curious.

Last year Action = Reaction Labs released Aves [Free], a (then) paid tech demo disguised as a archery game that featured both binaural 3D audio and an animation technology known as "BioReplicants". We explained what this all was in our review:

Aves uses GHOST binaural audio, which requires headphones, but creates an eerily realistic three dimensional effect to all the in-game music and sound. The animation technology in the game is called "BioReplicants," and has no preset animations for the birds flying around in the game. Instead, the physics model is built around a virtual muscular-skeleton system to create a bird rag doll that moves and flies identical to how a bird would fly in the real world.

At GDC this year, we met with the guys from Action = Reaction Labs, and while they weren't ready to show anything publicly, we saw what the next iteration of the BioReplicants technology looked like. Recently, they offered us a video of this all in action:

If you find yourself watching this video saying, "OK so why is a robot getting shot cool?" Well, here's the deal- iPhone games largely use completely canned animations for everything your character does from running, to jumping, to shooting. Quite a few iPhone games such as Stair Dismount [Free] use ragdoll animations which amounts to the game treating a model quite literally like a ragdoll and having it procedurally bounce off things with its limbs flailing to create more realistic death animations. Wikipedia does a great job of explaining how ragdoll physics works if you want to know more.

What BioReplicants does is sort of combine the two. With this technology, instead of how many games work, where you basically just shoot your opponents and the only feedback visual feedback you get is a little flourish around your crosshair until they finally just fall over dead, you'd see their standard shooting animation, modified in real time based on the forces your own bullets are exerting on them. If you look at the above video as "holy cow I can't even believe all the physics math going on behind the scenes" instead of "hey a robot getting shot," it can pretty easily blow your mind, especially considering that this physics engine apparently performs well enough to be feasible to use for iPhone games.

Like any tech demo, it all comes down to how the technology is eventually implemented in an actual game. Yes, the new BioReplicants stuff is cool, and I expect it to be downright amazing for people who have experience with working with 3D models and physics in video games, it's an uphill battle to make middleware like this interesting to your average gamer. Regardless, it's cool seeing what's technically possible, and I really look forward to seeing someone taking the BioReplicants engine and making something incredible.

For more demonstrations of BioReplicants in action, check out the Action = Reaction demo site.

That's right, Hurdle Turtle [99�]. TouchArcade cohort Eli Hodapp and I have been enjoying this silly game for the past couple of months since release, and felt it was high time for a full review. Sometimes its hard to explain exactly why someone likes a certain game, and Hurdle Turtle is no different. It's an endless running game that's certainly fun, but it doesn't do anything especially unique from the countless others out there. Still, whether its the hilarious front flips your turtle performs, the way it looks like he (or she) might be having a seizure while running, or the excellent retro chip tunes and blocky graphics, there's just something about Hurdle Turtle that makes it infinitely likable.

Hurdle Turtle has been around for a while now, as a Flash game and an Xbox Live Indie title. The goal is to run for as long as possible down a straight track while avoiding obstacles and keeping pace with an increasing speed. You can move in any direction while running, and bust wicked front flips with a jump button. You can even move around in the air during a jump, which adds a bit of strategy to how you deal with oncoming hazards. It's not groundbreaking for a running game, but it doesn't mess up the tried and true formula.

What really sets Hurdle Turtle apart is the awesome style of the game. Your turtle is cute, and has a lot of personality for a blocky sprite, and the retro chip tune music is catchy. A huge 2.0 update that hit last week added a ton of new content to the game, too. There is now a total of 11 different turtles to pick from, and three different environments to race in. The game keep track of your total distance run across all games, and each of these new items unlock at set different distance intervals, adding a nice sense of progression to the gameplay. High scores are tracked through a combination of OpenFeint and Game Center, with achievements to unlock as well.

This video shows the initial version of Hurdle Turtle on iPhone, back when it had only one character and theme, but you can check out the XBL version here which shows more of the stuff that is in version 2.0 on iOS:

Let's be honest, expectations run pretty high on the App Store, especially when you're talking about spending an entire dollar. I'm sure there are those who will wonder what exactly is so special about Hurdle Turtle, and complain that the graphics aren't as good as Infinity Blade [$5.99]. But at the end of the day video games are supposed to make you smile, and have fun during a quick break from real life, and I've been doing a ton of both with Hurdle Turtle. If you could use a bit of cute, retro fun and have some spare change lying around, give Hurdle Turtle a download.