Somebody let the zombies out, and they're on a serious rampage to get rid of the survivors! Shelter is a post-apocalyptic strategy game from Survivalist Games that distills all the running, shooting and getting your brains eaten action from surviving a zombie raid into a card game. It's surprisingly challenging and calls on more skill than just being able to place a few cards on the table. And just because zombies busting down the doors happens with cards doesn't mean it's any less thrilling.

The game takes place on a map where you can accept missions by tapping colored pins. Enter a duel and you'll see a spread with the zombies on the top and the survivors below. The gist of these battles is you're in a shelter and the zombies are trying to get in. By playing cards from your hand or using cards from the board you can barricade the doors, reinforce the structure, or do some good old fashioned zombie splattering. Turn them into gray goo and you can call it a win. But if the zombies deal you 50 damage, it's game over.

The artwork in Shelter looks as if it were ripped straight out of a graphic novel, which is a fantastic fit for the game and setting. The difficulty slowly increases as you work your way through the map, forcing you to be more frugal with your actions and refine your deck to a true zombie killing machine. Er, defending-from machine. The game's a little slow to begin, especially with the lengthy tutorial text that keeps popping up to explain every detail about playing, but it soon picks up and will have you hooked for hours. Despite one or two awkward interface moments, Shelter is a challenging and creative card-based strategy game that's sure to give you your zombie fix!

Super School Day is a quick-fire collection of mini-games from Second Impact Games. It shares a lot with titles like Wario Ware and the classic 4 Second series, though this game is out to make a mockery of them at every turn. Each round drops handfuls of extremely fast micro-games in your face, challenging you to complete them as best you can before you're whisked off to the next one. You will feel lost, you won't know what's going on, you will yell and you will fail. But you'll be laughing the whole time because hey, there's a sea urchin school uniform!

To start out, pick a student. Each has his or her own personality that affects which games you play and how difficult they are. You are then thrown into the craziness that is your "typical" day of school, involving things like landing a UFO, playing dodge ball, racing down the hall with fire extinguishers in rolling chairs, destroying a car with Street Fighter-style moves, and eventually trying to stop a meteorite with your bare hands.

What makes Super School Day so fun is its over-the-top personality. It knows it's a mini-game collection and it doesn't care. It throws stuff at you left and right secure in the knowledge that you're going to fail at some point. But you'll have fun doing it! Unlocking different endings is great fun, and attempting to perfect each challenge will take some work. This is a day at school, after all. You didn't expect to just show up and dance to a song about a giraffe, did you?

Little Luca from Glowingpine Studios is a unique one button physics puzzle game that puts you in control of a bunch of floating colored things that change shape. Really! As two friends gazed upon the peaceful night sky something terrible happened. Stars fell from their perches, leaving behind a glowing red void. And the only person/creature that can set things right is you. Time to get wobbling!

Levels in Little Luca are filled with objects the game itself describes as "wibbly-wobbly morphing" things. All you have to do is touch the forms to change their shape, using momentum and physics to catapult around the stage to collect stars and make it to the exit. Each shape morphs in a different manner when activated, leaving you some room to experiment and practice your timing before you get a perfect score. In later levels you'll unlock new things to play with, including gravity wells, tractor beams, whales, and maybe even a volcano.

The music and artwork in Little Luca deserves a mention, as both are spectacular in their own right. The game is a bit on the challenging side, but because everything in the world is so happy and cheerful, you never get frustrated, just motivated. Getting the hang of Little Luca takes some time, as it isn't your usual puzzle game by any means. But it's got all the ingredients of a solid mobile release, and you'll happily sit down and poke each little wobbly blob until the sky is filled with stars once again!

We're back with more games! More specifically a free game, a game that's on sale with a price that happens to be free, and a game about punching fish that isn't free but is close to it!

Free game: Puzzle Retreat - Earlier this year, The Voxel Agents released Puzzle Retreat. The game proceeded to rule our mobile devices with an iron fist, attracting our attention more than any other game. And for good reason, too: it's one of the most polished and entertaining puzzle games out there! To celebrate its awesomeness, Puzzle Retreat is currently free for iOS devices. The sale could end at any moment now, though, so be quick!

Free game: Apple Bin - Sometimes you just wanna throw some apples around. Apple Bin from Ruxar is a physics puzzle game that gives you a cannon full of apples and challenges you to do all sorts of stuff with them. Well, mainly get them in the bin using as few shots as possible, but in order to reach the bin you've got to avoid dangerous things and move some junk out of the way. Like giant concrete boulders, wooden planks, sawblades, portals, crates, gravity inversions, etc. It's a simple idea with a great implementation, and it's completely free from in-app purchases and all that other rubbish many mobile games like to feature. Just plain old apple-based puzzle solving! (Android / Windows Phone)

Almost free: Fish Puncher - Guess what this game's about? The official description says it best: "In a near-future dystopia, psychotic demon fish have enslaved humanity (for some reason or another - Global warming, probably). It's up to you, the Fish Puncher, to liberate us all in a convenient, two-minute burst of frantic arcade-style action. Punch stuff, punch more stuff, get a high score, be a hero." (Android)

Crazy Machines Golden Gears is a new addition to the Crazy Machines series of physics building/puzzle games. The franchise has made the leap from downloadable desktop game to the mobile world, bringing with it all the challenge, creativity and, well, crazy machines you can imagine. If Rube Goldberg only knew the kind of legacy he would leave to the casual gaming world.

If you've played the other Crazy Machines games or the granddaddy of all contraption-building games The Incredible Machine, you'll know exactly where to begin. Each level has a simple goal to accomplish, things like popping a balloon, getting a toy truck to the exit, or guiding a fragile vase to a marked platform. You do this by arranging an inventory of over 75 different contraptions, each more unusual than the last. How about dropping a basketball on that wind-up mouse to hit a button to set off the laser that pops the balloon? Or wiring up a logic gate that powers a boiling kettle that will move a turbine that pulls a conveyor belt? Yeah, you can do that. And it's awesome.

As the name suggests, golden gears play a big part in the mobile release of Crazy Machines. You're rewarded heaps of them based on how efficiently you solved each level, and in order to unlock additional stages, you've got to spend gears like mad. Two simple in-app purchases can help you in that department, and along with them you can gain access to a level editor as well as user-made levels. There are hundreds of custom stages to play, so if the main game isn't enough, Crazy Machines can still deliver!

Crazy Machines Golden Gears has made an easy transition to the mobile realm. Touch screen controls are flawless and it couldn't be simpler to place, arrange or remove items from the inventory. Now all you have to do is figure out how to solve these intricate puzzles and you're good to go!

In a situation that hits a little too close to home for some of us, Coolson's Artisanal Chocolate Alphabet from Things Made Out Of Other Things is a word game based in a chocolate factory starring an out of work English major desperate for a job. You manage to get a position at Coolson's factory packing boxes with letter-embossed chocolates. But since dropping squares into slots isn't all that exciting (and since you want to put that fancy degree to use), you decide to make things more difficult/entertaining for yourself. Instead of filling boxes, now you're writing words!

A conveyor belt at the top of the screen slowly moves pieces of chocolate from left to right. In the center is a small grid. Tap and drag letters from the belt to the box, arranging them so they intersect and spell short words, just like in a crossword puzzle. You have to work very quickly, though, as letters drop off the assembly line in a matter of seconds. You'd better have a good vocabulary and are comfortable working with awkward letters if you want to stay in the game. In fact, you might just need to be an English major!

Coolson's Artisanal Chocolate Alphabet can be an extremely challenging game, but not unfairly so. You can restart levels whenever you like with no penalty. It's easy to lose ranking stars by dropping too many letters in a stage, so be prepared to repeat workdays if you want a decent score. Best of all, both online and local multiplayer modes let you word/chocolate battle friends! Oh, and we can't talk about the game without mentioning the artwork. One glance and you'll fall in love!

It's tough to be a little element. You're at the mercy of every current of wind and lava flow on the block. Fortunately for the four elements in Element4l, they're bound together as a single entity and can switch as easily as you or I eat a whole bar of chocolate (i.e. instantly). This soothing but challenging arcade game from I-Illusions puts you in charge of those transformations, utilizing them as efficiently as you can in order to move through each stage safely.

Press the [left] arrow key to turn into a block of ice, [right] to switch to fire, [down] to turn into a stone, and [up] to become a floaty bit of air. Each of these states can be toggled as easily as you press the keys, and the physics associated with them will immediately take hold. Ice slides on smooth slopes and is great for building up speed. Earth is heavy and practically invincible. Fire lets you dash forward and bounce off of certain surfaces. As air you can tap [up] to float higher, letting the wind currents carry you where they may. You have an energy meter that prevents you from spamming the keys, so timing is everything.

Element4l starts as a little bit of a puzzle game that slowly morphs into an experiment in momentum. Because you don't have direct control over where you move, you have to take advantage of every environmental feature to ensure you stay on the move. One mistake and you'll likely have to restart from the last checkpoint. It's a bit frustrating at first, especially when you lose your speed and sit there like a grumpy little lump. Once you get the hang of it, though, it's an extremely satisfying experience. Accompanied by a beautiful soundtrack and lovely visuals, Element4l is a slice of beauty wrapped around a smoothly-flowing arcade game.

Windows:
Get the full version (requires Steam)
Get the full version (via Steam)

Mac OS X:
Get the full version (requires Steam)
Get the full version (via Steam)

Wyv and Keep: The Temple of the Lost Idol is finally here! After almost three years in the oven, A Jolly Corpse has released its fully-baked and delicious puzzle platform game to the masses. It's got excitement. It's got adventure. It's got treasure. It's got multiplayer co-op. And it's got enough challenge to keep you scratching your head for a very long time.

You control both Wyv and his buddy Keep as they work together to solve puzzles in a series of single-screen levels. The goal is always the same: get a crate on top of the button to open the exit door, then get someone to the exit. Actually accomplishing that is going to take some serious puzzle solving. Wyv and Keep can jump, pick up some items, push crates, and perform the occasional context-sensitive action like cutting a rope. Switch between characters as you position them in the correct places, using their noggins as temporary platforms to get everything where it needs to go. It's a lot like a simplified version of The Lost Vikings mixed with a touch of treasure hunting.

In addition to the main game, Wyv and Keep packs a level editor called Wyv's Cartographer that's surprisingly powerful. Not only can you create your own puzzles, but you can add custom artwork to make it look just the way you want. Map sharing forum thread, here we come!

Analysis: Wyv and Keep is a seriously challenging game. If you think you're going to blaze through all 60 levels without breaking a sweat, you're in for a surprise. Puzzles take on a strong order-specific nature to them, forcing you to work out what needs to go where and when it needs to go there. And just when you think you've got it all figured out, you realize one of your characters is left stranded in the corner by that crate you just blew up. Time to start over! It's the kind of difficulty that inspires you to press onward, though, so don't get discouraged!

The storyline in Wyv and Keep is ancillary, but because the pair is such a quirky comedy duo it falls in place quite nicely. As new environmental obstacles are introduced you get to read about them in journal pages left by a previous adventurer. It's great watching the characters react to things as simple as sticky mud or statue heads that shoot fire spears. Also, the animations are a lot of fun to watch, especially when Keep or Wyv starts crying when the other one kicks the bucket.

The only real drawback to Wyv and Keep is its insistence upon keeping score. A running total of the time you take staring at the screen is kept, and each time you die you incur a small penalty. That also includes restarting the level because you got stuck. This feels a bit like punishment for not being able to see into the future, but for many it's just further incentive to go back and get a better score.

Wyv and Keep has been a long time coming, but it was worth the wait. It's a polished and well-made puzzle game, and the addition of co-op easily pushes it over the line into exemplary status. A great game no matter how you look at it, just be prepared to do some actual puzzle solving!

Windows:
Get the full version
Get the full version (via Desura)

Mac OS X:
Get the full version
Get the full version (via Desura)

Linux:
Get the full version
Get the full version (via Desura)

Pet Rescue Saga is a cute and captivating puzzle game that made its way from the world of Facebook to the mobile marketplaces. Created by King, the developer behind Candy Crush Saga, expect a well-tuned matching experience punctuated by a number of useful power-ups, all told through a shoestring story about rescuing adorable pets!

At its core, Pet Rescue Saga is a lot like the classic puzzle game SameGame, a formula that has been remixed many times over the years. The screen is filled with tiles of various colors along with a few miscellaneous power-up and point multipliers. All you have to do is tap a group of two or more like colors and they disappear, creating space for the surrounding blocks to fall and squeeze in. By being judicious about which blocks you remove at what time, you can carefully carve out more and more space so the little pets you're trying to rescue can reach safety.

Pet Rescue Saga is a very simple game. King has experience turning Candy Crush Saga into a massive mega-hit, however, and it shows with this release. If you're worried about in-app purchases and the like, you'll be pleased to know that Pet Rescue Saga lets you play all you want, provided you keep winning! Meet the goals of each level and you'll continue unlocking stages as you complete them. Fail to meet the goal too many times and you'll have to wait for your hearts to refill. It only takes about an hour, but if you're impatient you can nab extra hearts via microtransaction or by asking Facebook friends. Very tastefully done.

It's a simple, quick game with a whole lot of replay value. Pet Rescue Saga has a lot of pick-up-and-play power and is perfectly tuned for quick rounds of mobile entertainment. Plus, you get to save cute piglets and bunnies and birds and puppies. That's never a bad thing.

Bridgy Jones, which we promise has absolutely nothing to do with Helen Fielding or Renée Zellweger, is a physics puzzle/building game from Grow App. It's pretty much free from all that romance and stuff, but it's still tells a bit of a love story in its own way. The love between a dog and a chicken, a man and delicious fried eggs, and you and your ability to make bridges out of thin air, that is.

One part Cargo Bridge and one (smaller) part Mining Truck 2, Bridgy Jones challenges you to create solid structures to help a train safely cross bigger and bigger gaps. Simply tap and drag to place items like rope, railings and planks, all useful for creating platforms and support pieces you'll need to distribute the weight. The train is hauling cargo, so the ride can't be too bumpy. Take it slow and make ample use of the game's friendly editing options to place, slide and erase parts as often as you like.

Bridgy Jones should be familiar to anyone who's played a physics building game before. It doesn't go out of its way to reinvent the genre, nor does it over-complicate things with too many building materials or crazy mini-games. It's simple, bridge crafting fun, with a lot of great artwork and a tongue-in-cheek storyline to boot.

Color Zen from Large Animal Games is a relaxing puzzle game that's probably going to be your next go-to for quick bursts of entertainment. Each level hands you shapes of various colors, some of which are movable, all you have to do is give them a quick swipe. When shapes of the same color collide they meld into each other and fill the entire screen, effectively eliminating that color from the puzzle. The goal is to get every visible object the same color as the border.

Color Zen becomes challenging when it starts playing with shapes nested inside of other shapes. If you want to get rid of all blue things, you have to make sure every blue object can be "touched" when you slam two blue shapes together. It's a bit like Factory Balls in that order is king. Think a few moves ahead and you'll do fine. There's no scoring and no timer, making this a great puzzler to sit back and relax with. Simple idea, great game.

Tiny little change for this week's Mobile Monday. We're going to start featuring a few free games each week along with some mobile games that didn't quite make the cut when we worked out the weekly schedule. Any objections? Didn't think so! Onward!

Minecraft mobile gets multiplayer - In case you stopped playing Minecraft for some reason, you should know that Minecraft: Pocket Edition recently had a rather significant update that added a sorely-missed feature: multiplayer! Mobile Minecraft is making use of the beta version of Mojang's Realms, an official service set to provide servers for all who play the game. For a fee. But it's free at the moment, so go and check it out! (iOS / Android)

Free game: Quadropus Rampage - One part roguelike, one part arcade smacking game. Quadropus Rampage from Butterscotch Shenanigans is what near-mindless button smacking should be. The game touts one of its features as "Hit enemies in their stupid faces", which we admit is really rather awesome. Randomly generated levels, tons of loot to pick up and equip, and some bright and shiny graphics that look fantastic on your Android device. And yeah, it's free! (Android)

Nearly free: Pixoban - Bringing a little sokoban action to the mobile markets, Pixoban stars the young Pixo who has been abducted by aliens. In order to escape, you have to puzzle your way through 126 levels of tough block-shoving puzzles. It's ok, though, because you might get a spiffy hat out of the deal. (iOS / Android)

Final Fantasy IV hits Android - It took its sweet time, but Square-Enix has finally brought the 3D remake of the fourth Final Fantasy game to Google Play. It's not on sale like Final Fantasy Tactics: The War of the Lions is (darn), but it's Final Fantasy, and it's still good! (iOS / Android)