Puzzle games also find a natural home on the iTunes App Store, and 180 is one of the more interesting ones. What would normally be straight-up Bust-a-Move clone takes things to a different level by adding an extra dimension to the gameplay. Tap an empty area of the screen to fire pieces towards the top, your goal being to line up three identical colors. Each piece has a flipside, however, and you can toggle them around with a simple tap. This allows you to create some big combos and adds a little thinking to the process instead of just recognizing a color and firing away.

Similar to Doodle God, Alchemy Classic is (apparently) based on an old MS-DOS game. Alchemy works exactly like you would expect it to, with a simple drag-and-combine interface that makes it easy to experiment and try theories. Tap the icons at the top of the screen to clear the board, undo your last combination, see created elements along with elements you can create with your current outfit, and go to the element adding menu where you can choose icons to drop on the playing field. Double tap any element to clone it, and double tap an empty part of the screen to spawn fire, earth, air, and water. Simply drag elements onto each other to try combining them. If they can mix, they will, and your new element is born. It's all about experimenting, and it's every bit as captivating as you think it would be. Hundreds of combinations are possible!

Another area that's ripe for puzzle exploration is water running through pipes. Aqueduct takes this to a simple new level by combining pipe tiles with a sliding puzzle of sorts, challenging you to not only move the right pipe pieces in the right place to let the water flow, but to move them without blocking each other's path. If you hate sliding puzzles like me, you won't have anything against Aqueduct, as it's pure puzzle awesomeness, plain and simple. And you gotta love that visual style!

Hey, you played the extraordinary puzzle game Ynth, right? You know, the one where you control the little beetle who moves through the sludge by pushing boxes around, and that was previously recommended here? If you didn't, you're missing one of the App Store's most original and most darling puzzle games. After you rectify that misdeed, grab the sequel, Beyond Ynth. Like the title suggests, this one takes the original formula a step further, adding nicer visuals, better puzzles, some gameplay refinements, and a whole host of new levels. It's an excellent follow-up to the original game and should not be missed!

Simple, stylish, and challenging, Clock Blocks is a great puzzle game that combines reflexes and planning in a unique package. When a level begins, a ball flies on screen and lands on one of the clocks. The hands of each clock are constantly spinning, and when the ball touches it, the hand starts drawing a gray background. You must tap the screen to fire the ball in the direction the hand is pointing before the circle is complete. After you fire, that clock disappears, so the goal is to lob the ball from clock to clock until the screen is clear. Three modes of play are available, from quest to survival to classic, the former being a more puzzle-oriented experience while the latter two are all about speed and accuracy. It's a wonderful puzzle game that's filled with levels and that simple kind of challenge we love to see in our mobile games. The free Clock Blocks Lite is available, and you can also try the browser version of the game to get a feel for the mechanics before downloading.

You've probably seen every matching puzzle game in the world by now, but you haven't seen Colorfall. Your task is to match the falling blocks in the order of the colors of the rainbow ó red, orange, yellow, green, blue, indigo, and violet, or ROY G BIV. Any three colors in the right order will do, and it quickly becomes challenging to remember the order when blocks keep falling from the sky. As an extra bonus, iPhone owners can snap a picture with their camera to change a block to the most dominant color in that image. A very unique match-3 game you'll have a great time learning to play!

From NimbleBit, creator of Textropolis, Fishtropolis, and several other games, comes a simple one-switch game involving a frog, some lily pads, and a little timing. Jump from lily pad to lily pad by tapping the frog at just the right moment. Each pad rotates when you're sitting on it, so you have to gauge distance and time your jumps just right. Land in the water and you lose a life, leap over a lily pad and you gain a life. See how that can lend itself to nigh-infinite playtime?!

The baby cousin of Little Things and a more grown-up version of Super Search 60, Doodle Find is an object finding game that takes only 90 seconds to play. Each self-contained round starts with a handful of scribbled items on the screen. Check which item you need to find at the top of the screen, then tap it to get another task. It's every bit as addictive as Super Search 60, but the new visual direction, the added time, and all of the other little extras make it feel even more polished.

The tantalizing Flash game is now on your iPhone! You start with just a few elements ó air, water, fire, and earth ó but must combine them to eventually form well over 100. Tap one category to open up its sub-types, tap another to bring it up on the other side of the screen, then tap two elements to see if they mix. If they do, you get a brand new element to play with. If they don't, you get nothing and must keep trying. It's a bit trial-and-error in nature, but superbly captivating all the same.

From the creators of the unbelievably appealing Textropolis comes another word game where you spell words from other words! This time, instead of picking apart city names, you're working with fish. That's right, fish. How many words can you spell using the letters W, H, I, T, E, C, A, R, P? Hope it's a lot, because you'll need to cull dozens upon dozens of words out of each name before you can move on to the next stage. Challenging, but boy will you have a great time.

Ooh, hello puzzle game with an attitude! Play as Helsing and Raffton as they set out to rid London of the stinky menace that is evil. Nasty enemies inhabit every corner of the city, but you're armed with torches and tonics! Place the torch to light up as many enemies as you can, then drop a tonic to send them packing. Enemies can be different colors, requiring a different kind of tonic, and some come with shields or the ability to mess with your torch. A wonderfully crafted puzzle game that's full of personality and wit. The various victory fist pounds/high fives the duo gives each other after each round makes the game worth grabbing!

Oh. My. Stars. This game is grand. You're a comet and you are exploring the galaxy. Tap a planet and you start to orbit it. Swipe the screen to let go and fly across the black sky. Eat floating space debris and you'll slowly build a "warp" meter that allows you to cover a great deal of distance in a short time. Your only goal is to check out the universe and see what's out there, and boy will you have a great time doing it. The artwork (by Niklas Åkerblad) for this game is nothing short of phenomenal, and the whole experience is simply marvelous. Fun fact: Kometen was designed by Erik Svedäng, creator of Blueberry Garden.

Another great puzzle game, this one takes the familiar gem stacking concept to a realm of cheesy space sci-fi. Our hero has crashed on an alien planet, and the local inhabitants aren't too pleased about that. Orb-like aliens pile on top of your shield, and they have but one weakness: being grouped together in like-colored columns! Use your gun to pull Linkoidz through the shield and shove them in other stacks. Match three or more and they vanish, creating chain reactions, breaking ice blocks, and doing all sorts of other neat things. A sometimes frantic puzzle game that's just as much action as it is thinking (zen mode tilts it to the former a bit), but it's a great time killer for the mobile platform.

More Moxie for you! The thoughtful word game of strategy returns with more challenges and a daily puzzle feature. An empty grid sits in front of you and letter tiles appear one at a time on the right. Spell words using these letters, swapping them whenever possible to score points. New in the sequel are pre-set word challenges that fill the grid with tough words to see if you can get a global high score. It's tough, for sure, but an extremely satisfying word game.

Come on now, say it like you see it: NOBY NOBY BOY! With loud exclamatory voices! This gem of a game comes from Keita Takahashi, creator of the Katamari Damacy series, and is based on the PlayStation Network title of the same name. Rather than putting a quirky game in front of your face, NOBY NOBY BOY is more like a wildly interactive toy. The "goal" is to stretch the main character (the "boy") out as long as you can so he can add his length to the cosmically-proportioned "girl" in the hopes that she can unite all things in the galaxy. Yep! Wholly unique when compared to its PSN cousin, and wholly unique when viewed by itself. It's so absolutely charming you can't help but love it.

Games like Pinch are uniquely suited for multi-touch devices such as the iPhone and iPod Touch. Guide your orbs through each stage to the goal, passing locked gates, pushing buttons, and surviving other hazards along the way. If you need to fit through a small gap, simply pinch and separate an orb into two smaller ones. If you need to create a new color or fit over a hole in the floor, pinch and combine orbs. A nice idea that works very well on the mobile platform, though why it's orientated in portrait mode instead of the more friendly landscape mode is beyond my comprehension.

The extremely colorful puzzle matching game is back with a sequel worthy of bearing the number "2". Slide your finger across the screen to swap blocks and make matches of three or more like colors. You can even string combos together for extra points, and the occasional power-up adds a nice destructive flair to the experience. Four single player modes are available, along with a brand new two player mode you'll have a great time toying around with. A lot of content for a match-3 game, and it looks and sounds great, too!

If you enjoyed Unify (and you really, really should have), Sigma will get your brain going in much the same way. Two cylinders of tiles face each other from either side of the screen. Use your fingers to rotate the shapes and tap the screen to send the middle block to the other side. Make matches of three or more and you'll chisel away at the cylinders and eventually progress to more difficult levels. Great design, smooth gameplay, and a colorblind mode makes things especially friendly for all players.

Say hello to your new puzzle/RPG hybrid addiction. Sword & Poker combines dungeon crawling with elements of poker, allowing you to drop two cards around a set of cards to make the best poker hand you can. Not familiar with poker? You don't have to be. After one or two fights you'll get the hang of the setup and be dispatching bats with the best of them. Loot treasure, buy better weapons, and dig as deeply as you can into the depths of the cave. An excellent game with a fantastic presentation, smooth gameplay, and just the right level of complexity to make it hideously addicting. Do yourself a favor, skip the Sword & Poker Lite version and go straight for the real deal.

A blue train wants to leave the station and make it to the blue goal. There's no track, unfortunately, so it's your job to draw it. Now, what if a red train and a green train leave separate stations and want to reach the same goal? That'll require a bit more track, a few track switches, and a little thought. What about combining trains and trains that need to change color? That will require a lot more thought, a lot more track, and probably a few tricks you've never thought of before. An excellent puzzle game with loads of levels and a wonderful level of challenge. You'll never get tired of this one. Seriously.