We've seen many of our favorite games updated in the last few weeks now that Apple's Game Center has gone live. Predators by Chillingo is next in line, and one of the more premium apps to receive a little extra achievement love to extend its lifespan. Thankfully, Chillingo and developer Angry Mob Games have taken this opportunity to renew interest in Predators with additional levels, weapons and other content, too.

Since the last we looked at Predators, where we were impressed by just how faithfully it captures that authentic Predator feel, it has been updated (in version 1.2) with Retina Display support for you lucky 4th gen owners. Of special note in the new 1.3 update are two new survival modes which thoughtfully address criticism in our review that the initial offering of just one survival level got a little too repetitive.

The developers have also added additional weapons, such as the useful long-range melee Razor Whip, and a host of new combos to go with it. Of course, Predators wouldn't be much without enemies to use said weapons on, and so 3 additional (and challenging!) enemy Predators have been added as bosses to make use of these new abilities; the final Super Black Predator said to be quite ferocious and a real test of your accumulated skills.

We're still playing through Predators again to unlock the new content ourselves, but we're pleased to see that there are now 31 achievements to work towards in Game Center, and all the high score tables have been ported over to Apple's new platform too. We're glad that Chillingo have stepped up and responded favorably to our feedback, and we're confident that all the new additions (and the temporary price drop) will entice fans back to the game for another play through and attract newcomers too, particularly if you're a 4th gen device owner and missed the Retina update.

Back in July we brought word that Gaijin Games had teamed up with Namco Bandai to develop an iOS adaptation of Gaigin's Wiiware rhythm action title BIT.TRIP BEAT. We're happy to report that the fruits of their labors have just made their App Store debut, with a version for both the iPhone / iPod touch [link] and the iPad [link].

One of a series of four�Bit.Trip titles by Gaigin (published through the Wii Shop by Aksys Games),�Bit.Trip Beat is something like a cross between�Pong and�Rez as an accelerometer-equipped Atari 2600 might play them. The game puts you in tilt or touch control of an on-screen paddle with the goal of bouncing waves of oncoming blocks whence they came. The impact timings of the aforementioned blocks are synched with the excellent chiptune audio track while abstract / futuristic animations float in the backdrop, both of which give the game its sort of�Rez dynamic. And, it's all done up in brilliant colors and oh-so-lovely jaggy, chunky pixels, with a chiptune soundtrack appropriately accompanying the on-screen action.

The further you progress through the game, successfully returning oncoming blocks, the more complex and evolved the visual presentation becomes. Miss too many blocks, and the visuals slowly regress to a simple, black and white state, in another apparent nod to�Rez.

Says Gaigan founder Alex Neuse,

"We're very excited for the BIT.TRIP series to join in the fight against digital boredom alongside the rank and file of legendary Namco franchises, such as PAC-MAN, Katamari Damacy and Mr. Driller. When considering a publishing partner for our series on mobile devices, Namco was among our top choices. After playing the final iPhone version, we positively freaked out. Namco has brought an absolutely pure BIT.TRIP experience to the mobile market and we look forward to continuing the series with them."

And I'd have to agree with Neuse as regards the "pure" nature of this game on the iOS platform, if "pure" speaks to a faithful, well-implemented conversion. I've spent significant time with the Wiiware original, and the game plays wonderfully on the iPhone and iPad. In fact, I find that the game offers more precise controls on the iOS devices than it does using the Wiimote � in touch-control mode in particular (though tilt is also an option). In my opinion, it's more enjoyable on the iPhone or iPad than on the Wii.

BIT.TRIP BEAT features local and online multiplayer (through Game Center), but at the moment it's only two-player head-to-head � four-player is coming in a future update. What's more, three additional levels (for now) are available as in-game, downloadable content. (One of the complaints about the original is the somewhat limited gameplay content.)

See the developer's short trailer featuring a bit of gameplay, or have a look at the Wii video we posted earlier, featuring nearly identical game content.

BIT.TRIP BEAT is one of those games that draws you in and sends you to a sort of 'zone' where much of the mundane meatspace world just kind of falls away. Anyone who enjoys rhythm gaming or retro-styling in general should have a really good time with this one.

BIT.TRIP BEAT for the iPhone and iPad are currently on a limited time, 50% off sale at the time of this writing.

From the "better late than never" department of the TouchArcade command center comes news of an update which just hit the App Store mere moments ago for Gameloft's Rogue Planet [$4.99 / Free]. Rewinding all the way back to WWDC last year when we first got a peek at the game before it even got picked up by Gameloft, Aurelien Kebeci, CEO of the French development group Agharta Studio mentioned online multiplayer coming in a free update.

When Rogue Planet was finally released, we thought it was great in our review, providing a surprisingly deep (and great looking) turn-based strategy experience, although we were disappointed by the lack of multiplayer options. Today's update implements complete online multiplayer, and much like similar games, can support up to 32 concurrent games at once.

The update just went live, so there doesn't seem to be anyone around to play with yet, but we've really got to commend both Gameloft and Agharta Studio for sticking to their promise of providing online multiplayer. If you caught our original review and were waiting for the multiplayer update, or have since removed the game from your device, now is the time to either download the game or resync it to give online play a try.

Our favorite bird flinging pig poppin' game Angry Birds [99� / Free / HD] hardly needs an introduction anymore. Everyone from friends of mine who staunchly consider themselves non-gamers to random people of all types I end up waxing iPhone games with either have heard of, played, or in some cases, are even working on clearing the whole game with 3 stars. Of course, the game still has a little way to go before it eclipses Doodle Jump, as I haven't seen an angry bird on stage at a Lady Gaga concert yet, but the upcoming plush toys are a good start.

The latest update might be the best one yet. Game Center integration supplements Chillingo's Crystal adding achievements and even online leaderboards, giving a whole new purpose to revisiting old levels to beat the scores of your Game Center friends. Crystal achievements seem to transfer over, so be ready for some huge achievement spam the first time you launch the game after updating.

Angry Birds has been high up on my list of favorite iPhone games for quite a while now, but I hadn't been playing it much since I got my iPhone 4 as the game looked worse than most when upscaled to the resolution of the Retina Display. The game pulls a complete 180 with this update, as the new high resolution graphics makes Angry Birds one of the best looking 2D games I've played on the iPhone, and the amount of detail you can see when zoomed out now is really amazing.

Of course there's 15 new levels to plow through, adding even more content to a game that is already stuffed to the brim. Don't waste any time updating Angry Birds, and if you haven't downloaded this game yet, you're really running out of reasons to hold off, as the amount of entertainment you will get out of this 99� purchase is mind boggling.

We thought we'd seen the peak of innovation this week when ARDefender showed just how an augmented reality game should be made. Revolutionary Concepts and indie developer Nicolai Troshinsky had other ideas though, and have delivered something truly…well, revolutionary. If Augmented Reality is the idea of superimposing a game world onto your real world, then what has been done in UFO on Tape [App Store] can only be described as Transplanted Reality� a window into another world right in your hands.

UFO on Tape is a straightforward concept delivered in the most captivating way. It starts by showing you a re-created view of an iPhone camera (no actual use of the camera is ever made), as if it were pointed out the window of a car. Your girlfriend next to you then tells you that she's seen something strange in the sky. With your camera, you zoom in on the object, only to discover it is in fact, a UFO. As it darts around the sky and weaves amongst buildings, your task is to keep the zippy UFO firmly locked in your sights.

UFO on Tape delivers its incredible realism in two ways� firstly, through a pixel-perfect, photo-realistic representation of a video reel; and secondly, through the use of the iPhone 4's gyroscope, or if unavailable, the accelerometer. These two mechanics go hand in hand to make it actually seem as if you are controlling a camera phone and pointing it at something in the sky, all while looking through its viewfinder.

Naturally, use of the gyroscope is preferred, as it allows you to orient yourself to the ground and move the camera around as if it were actually in your hand, giving the most accurate experience. That's not to take anything away from the accelerometer though, as both functioned well to deliver similar results (if less dramatic on the older devices).

The game itself is extraordinarily simple, but also very challenging. The pesky UFO seems aware of your attentions, darting backwards and forwards at varying heights� frequently trying to lose you amidst the tops of buildings. Not only that, but it occasionally darts into your peripheral vision too, which is restricted by the blur of the outline of your car window. Explaining this in words is already doing it an injustice, but it is the most amazing thing to witness your game world restricted by something as routine as the view out your car window.

The entire experience is further enhanced by the interaction with your girlfriend. As you hone in on the flying saucer she'll make all kinds of comments; ranging from stunned disbelief to utter dismay if you happen to lose your target. If it does get away, she'll quickly start barking orders trying to direct you in the way it seems to have gone. Her fully voiced lines flow seamlessly are surprisingly plentiful� in the 30 or so games I played, I was frequently surprised by the new comments that pop up, there are that many. The dressing down she gives you from time to time� "You idiot! You lost it!"� and certain other memorable comments never tire, either.

The ambiance in UFO on Tape also deserves a special mention, as it has been meticulously crafted to such a degree of accuracy that it almost goes unnoticed, as it does when you're really driving. If you do hone in on it though (headphones help), you'll notice the sounds of the city behind you, from the purr of your own engine, to passing cars, sirens in the background and even the tick-tick of your turn signals as the car presumably negotiates the streets to afford you the best view. A creepy, X-Files like soundtrack really underlines the excellent audio work in UFO on Tape.

UFO on Tape is a singular experience, not for its dramatic level of content and replayability� in fact, the game itself is quite basic, with a standard high score table recorded on Game Center� but for the immense attention to detail needed to successfully bring its world alive in the palm of your hand. The true-to-life look, sounds and handling all come together to deliver something really special that simply must be played to be believed. We're telling you now, screenshots do not do this game justice, so get out and grab UFO on Tape pronto if this review has even piqued your interest in the slightest.

A couple of weeks ago we took an exclusive hands-on look at the puzzle platformer GravBot [Free] from Team Phobic, the developer responsible for games like Bounce On [$1.99/Lite], Bounce On 2: Drallo's Demise [$3.99/Lite], and Tunnel Shoot [99�]. Earlier tonight, the game went live in the US App Store. GravBot is free to download and initially comes with 12 levels. These levels ease you into the game mechanics and give you a great taste of what GravBot has to offer. If you like what's contained in this glorified demo, then there are two additional level packs available as in-app purchase. Each of these level packs contains 20 increasingly difficult levels, and are 99� apiece. Here is an excerpt from our hands-on preview talking about the gameplay in GravBot:

In�GravBot, you'll play as a tiny robot who must collect all of the batteries on each perilous level. In order to accomplish this, you can spin the entire level either 90 degrees left or right or entirely upside down to change the direction of gravity. Your robot can travel left and right on its single tire, and will fall towards whichever way happens to be down at the time. Levels are filled with hazards like spikes, enemies, and lasers which will kill instantly if not avoided. The batteries can be tricky to get to, and a color-coded system of trapdoors, elevators, and various other obstacles will need to be triggered by switching a lever or pushing blocks onto buttons � all in the name of snagging every last battery on a given level.

While just completing each level is sufficiently challenging and fun, the real hook toGravBot is trying to obtain gold medals for each one. The game keeps track of how many times you switched gravity to complete a level, with bronze/silver/gold medals awarded for using it efficiently. What is really satisfying is when you figure out a way to win gold using fewer gravity switches than is required. Due to the physics engine in the game, you can sometimes make it to a hard to reach area without changing the gravity and instead gliding through the air or just barely catching the edge of a platform and hanging on.

There's really not anything I don't like about GravBot, and it has become one of my most favorite puzzle games that I've played on the iPhone. The graphical style is cute, with support for Retina Display, and the GravBot robot exudes a ton of personality in the game. The levels are all really cleverly designed, and there's a tremendous amount of replay value going back to each one and trying to complete it in the most efficient way possible, earning medals and competing on the Plus+ leaderboards as you go. There's no risk in downloading the game for free and trying out the initial 12 levels, and the IAP level packs offer a great value for money if you're looking for more. In fact, I would love to see some additional level packs released down the line sometime. Players in our forums are enjoying the game�as well, and it appears that the talented folks at Team Phobic have another hit on their hands with GravBot.

We're not sure what has possessed the publishers of dozens of amazing iPhone games to decide that tonight was the night to hold a massive sale � but it's happened. And you can benefit from it.

A huge number of high profile games have dropped in price to all time lows. The number of high quality games you can pick up for $0.99 right now is amazing. We hand picked a few to highlight here, but below we've listed dozens more. Every game on this list is worth the sale price, so now's your chance.

A few notable games dropping to $0.99 include:

Osmos, $0.99 Osmos was originally released in late August of 2009 for the PC, and went on to win numerous awards. The multi-touch controls work wonderfully on the platform and it's a natural fit for the iPhone. We highly recommend picking this one up. Review

Spider: The Secret of Bryce Manor, $0.99 We choose Tiger Style Games' Spider: The Secret of Bryce Manor for our 2009 Game of the Year. Spider is an original concept built specifically for the iPhone by a small self funded team. Review

2K Sports NHL 2K11, $0.99 It wouldn't be hard for NHL 2K11 to claim the title of best ice hockey game on the iPhone, since the competition is sorely lacking. But it surprisingly goes above and beyond and offers a truly full-fledged NHL experience on a mobile platform. Review

Archetype, $0.99 Archetype delivers one of the most robust, beautiful, and most importantly fun first person shooter (FPS) experiences that can be had on the iPhone. Review

Here's the rest of the list, grouped by price. Unfortunately, this appears to be an iPhone / iPod Touch phenomenon mostly. Only two games (marked below) are iPad native.

$0.99

• Civilization Revolution ($6.99 -> $0.99)
• Soccer Superstars ($2.99 -> $0.99)
• 9 Innings: Pro Baseball 2011 ($4.99 -> $0.99)
• Baseball Superstars 2010 ($2.99 -> $0.99)
• Need for Speed Shift ($6.99 -> $0.99)
• Bookworm ($2.99 -> $0.99)
• Geometry Wars: Touch ($4.99 -> $0.99) Universal
• Puzzle Agent ($4.99 -> $0.99)
• Monkey Island 2 Special Edition ($2.99 -> $0.99)
• The Secret of Monkey Island Special Edition ($2.99 -> $0.99)
• Doom II RPG ($3.99 -> $0.99)
• Assassin's Creed II ($5.99 -> $0.99)
• Zombie Infection ($2.99 -> $0.99)
• Peggle ($2.99 -> $0.99)

$1.99

• Crash Bandicoot Nitro Kart 2 ($4.99 -> $1.99)
• Risk: The official Game ($4.99 -> $1.99)
• Hybrid 2: Saga of Nostalgia ($4.99 -> $1.99)
• Zenonia 2 ($4.99 -> $1.99)
• Castlevania Puzzle: Encore of the Night ($4.99 -> $1.99)
• Mirror's Edge ($4.99 -> $1.99)
• ACE Combat Xi: Skies of Incursion ($4.99 -> $1.99)
• Myst ($4.99 -> $1.99)
• Doom Resurrection ($6.99 -> $1.99)
• Sonic the Hedgehog 2 ($5.99 -> $1.99)
• Tony Hawk's Pro Skater 2 ($4.99 -> $1.99)
• NCAA Football by EA Sports ($4.99 -> $1.99)
• Command & Conquer Red Alert ($4.99 -> $1.99)

$2.99+

• NFL 2011 ($4.99 -> $2.99)
• Real Racing ($4.99 -> $2.99)
• Call of Duty Zombies ($9.99 -> $4.99)
• Call of Duty Zomies HD ($9.99 -> $4.99) iPad Only
• FIFA 10 by EA Sports ($6.99 -> $4.99)

The newest game from developer John Kooistra and Cat in a Box Games, Blue Defense: Second Wave! [99�], has just been released to the US App Store. Blue Defense: Second Wave! is the sequel to the 2008 game Blue Defense! [$1.99] that was one of the earliest success stories in the fledgling days of the App Store. Blue Defense! became popular by offering a challenging game with simple mechanics, clean graphics, and smart use of the unique strengths of the platform. Blue Defense: Second Wave! retains these core beliefs, and expands on them in a number of ways to provide a game that feels both fresh and familiar. Here is an excerpt from�our hands-on preview that explains some of the gameplay found in Blue Defense: Second Wave!:

The basics of Second Wave remain the same. You'll fight off waves of enemies with a perpetually shooting cannon firing from the center of the planet which you're trying to protect. A population of about 7 billion people act as the life of your planet, with that number dwindling with every enemy that penetrates your defense. If the population hits zero, the planet is lost and it's game over.

One of the biggest changes this time around is the ability to fire multiple cannons at once. Touching the screen at any time brings up an aiming reticule and a new stream of fire, with multitouch support for adding up to five additional streams along with the first cannon. A quick double tap on the screen locks an aiming reticule in place at that point on the screen, which can be dragged around and set anywhere you want to direct more firepower.

…

Besides the ability to add streams of fire, you also get a new weapon in the form of the planet cannon. Touching your planet and swiping in the direction you want to fire launches a humongous beam of destruction that's as wide as the planet itself. The planet cannon vaporizes anything in it's path, but comes with limited uses.

If you were a fan of the first Blue Defense! then you will most certainly enjoy this new sequel. If you somehow missed out on the first game, then Blue Defense: Second Wave! offers a stimulating shooter experience with unique mechanics that have evolved and been refined in the nearly two years since the first release. Best of all, Blue Defense: Second Wave! is launching at a special introductory price of just 99� through this weekend. It's also a universal app that will run on all iOS devices and has graphics that support the Retina Display. With 64 levels to play, more than 200 medals to earn, multiple modes of play, online leaderboards, and more, there is a ton of content for the price and Blue Defense: Second Wave! is a game that's not to be missed.

Just two days after we took a hands-on look at ARDefender from developer Int13, the game has now become available in the App Store as of this morning. What is a nice surprise is that the game has launched for just 99�. In ARDefender, you'll print out a special PDF image from ARDefender.com that is read by the software and creates a 3D tower in the real-life space of the iOS device camera's view. Enemies then attack the tower from all angles, and you fend them off with a weapon placed on top of the tower. You'll have a machine gun, rockets, and a laser at your disposal as you take on the endless waves of increasingly difficult enemies.

It's a cool concept and one that works really well in practice. I was blown away with how convincingly the tower seems to actually exist in the area where you're playing the game. The gameplay itself is also quite fun, although pretty bare bones. There's really only one mode to play through in ARDefender which has you defending against seemingly endless waves of enemies. Beyond that, there's not a whole lot more to the game. I'd love to see something along the lines of a story mode, different styles of towers, or online leaderboards and achievements. Still, what's here in terms of gameplay is pretty darn fun anyway. This video shows off one round of ARDefender as well as me playing around a little with how the technology works:

One thing that is important to take note of is that ARDefender will not work with the original iPhone or iPhone 3G. It would make sense that the older iPod touches would not run the game as they don't have an external camera (the game does run on the new camera-enabled 4th generation iPod touches by the way), but apparently ARDefender requires some processing power that needs at least a 3Gs iPhone or above.

Normally when a game only has one mode to play with not a lot of bells and whistles, it can be hard to recommend as those games tend to get old pretty quickly. In ARDefender's case however, the technology is just so impressive and the gameplay is so well done that it's hard to pass on the game when it's only a dollar. It's definitely something you'll want to show off to your friends because it's so neat, and players in our forums are already finding all of the wacky places they can place the PDF image and play the game (including pulling up the image on a second Apple device and growing the tower right out of that device's screen). If you have a dollar to spare and a capable device, you should definitely give ARDefender a try.

John Carmack, technical director of Id Software and founder of Armadillo Aerospace, has a lot on his hands these days. Aside from building rockets, he's also been hard at work on Rage, an upcoming first person shooter. Not much is known about Rage yet, aside from a few details that have leaked out along side the various game trailers over the years it has been in the works.

Carmack went on to surprise everyone at QuakeCon this year when he showed the game running at a solid 60 fps on an iPhone 4. Rage is still in development for both the PC and iPhone, and won't be released until next year. In the meantime, John Carmack has stopped by our forums and is asking forum members what things they commonly see developers doing wrong in iPhone games. He's compiling these suggestions in to a list that Id Software is going to do their best to adhere to them in future titles.

If you've got something you'd like to see become standard in iPhone games, please leave your comments in John's thread.