If you don't own an iPad 2 and you're about to skim past this post, let me interrupt you for a second. You can play most of Rebuild [$2.99] right now for free, as the Flash game Rebuild 2. And you really should. While the iPad 2 version comes with a few extra bells and whistles and plays gorgeously on a touch screen, this is a game that everyone should play whether they have the newest, shiniest gadget or not. Just be prepared to lose a few hours of your life to it when you do.

I don't wave around non-words like "unputdownable" often, but Rebuild deserves it. Though it's not an especially deep strategy game, it has the perfect mix of exploration, danger and difficulty to hook anyone for at least an hour or two, and maybe much longer. And yes, yes, we're up to our necks in zombie games, but this is a zombie/strategy/city builder and that's not something you see every day.

So here's the premise: you are the leader of a tiny outpost of survivors in the midst of a city overrun by zombies. Your few city blocks aren't enough to sustain your people for long, so you need to branch out. But danger lurks all around. Throughout the game you can explore the blocks around you, rescue survivors, scavenge for food and supplies, and reclaim land � all while defending against waves and hordes of zombies.

But first you need to establish your scenario. You can build a character, male or female, with an odd but broad selection of faces, hair styles and accessories. You can name your town and pick a piece of starting equipment. And then you can define the difficulty. Your town can range from small to huge, which establishes the length of the game. The difficulty ranges from very easy to impossible, and those are pretty accurate descriptions.

So you set out with your merry band on your few small squares of land. Each turn you can send your fellows out on missions. You might scout a nearby block. Following that, you might send a few guys to clear out the zombies so you can claim it as part of your town. Rebuild is a numbers game -- stack enough of one stat against an appropriate challenge and you will be guaranteed to overcome it. The game will even inform you of your odds.

But there are several stats to balance, and things become more complex as your city grows. And while it might seem like a good idea to keep everyone busy, you never know when Zed will attack. If your city is undefended, an attack might leave you with fewer survivors and more dead.

As you progress through the game you have to strike a balance between recruiting enough survivors to keep progressing, having enough housing to keep them, and finding or growing enough food to stave off starvation. Random events happen at the end of most turns, and they might make things easier or more difficult. As leader, you'll often be called on to make difficult choices.

These choices often tie in to the multiple available endings, and they're often intriguing. Do you act in self-interest or work for the good of the group? Do you let religion take hold, or attempt to stamp it out? And ultimately, once you've found a way to survive do you take it or do you keep going, trying to find something better?

These decisions feed into your final score. You're ranked on how long it took you win (or lose), how much you did with your time in zombie land, how difficult your game was and how many endings you found in one go. It's a great way to inspire players to keep trying for all the endings, keep playing, keep exploring. Be warned, however, that there's no way to track your success. There are no leaderboards, local or otherwise, so you won't have the chance to compare your progress through different runs. It's a serious oversight, but one of very few.

Otherwise, Rebuild is a treat. It comes with charming art, although its character portraits border on the surreal. The soundtrack is creepy and ambient, a perfect accompaniment to the bleak world the game inhabits. It's good enough that it makes me forget how tired I am of zombies. Rebuild probably won't satisfy fans of intensely deep strategy, but for anyone interested in a few hours of light strategy fun, it's quite the catch. Check it out, and share your thoughts in our discussion thread.

Paul & Percy [$2.99] is a great little platform-based puzzle game for the iPad, released by Danish developers�Kipper Digital.� When they discover someone has stolen their butter biscuits (or "cookies", if you're American), Paul and Percy set-off on a mission to recover their delicious snacks. The two main characters look identical, so perhaps they're twins. Otherwise, they're just two dudes who live together, dress alike and share butter biscuits.

The interesting thing about this game is that the screen is split down the middle, with Paul on one side and Percy on the other. It's like taking two platform games, turning them sideways and then placing them against each other. Each character has their own separate platform level to walk around.� But, they can stomp on certain brown blocks to push them through to the other character's side.� So, when Paul stomps on a block, it becomes a step for Percy (and vice versa). By helping each other, they can both reach their teleportation portal and escape the level.

This is one of those games where you stare at the screen for a while and then suddenly experience a wonderful eureka moment when you spot the solution. Of course, once you rush ahead with your brilliant plan, you invariably discover that Paul or Percy is stranded and needs an extra block to climb somewhere. Luckily holding your finger down reverses time, so you can back-track your movements � even right back to the start � and try again (or just hit the restart button).

Once you complete one of the fifty levels, the adjacent levels on the world map are unlocked. However, to score a medal (gold, silver, bronze) you need to complete the level within a certain number of moves. Each step, jump or character switch counts as one turn. So, don't absently walk your character around while you're pondering, because the gold medals require a perfect solution, without any unnecessary moves.

As you progress, other game elements are introduced. There are statue pieces to push into position, slug-like "snails" which can be pushed to the other side, but may come out somewhere different than expected.� Stomping on bells will make snails appear or disappear from the blocks.� Every few levels, there's a cut-scene to progress the storyline. And, of course, there's hot (as in stolen) butter biscuits to recover.

You can complete the game and solve the mystery without picking up any delicious biscuits, but they're required for achievements if you want an extra challenge. On the world map, levels with uncollected biscuits have a faint white glow. Once you recover the biscuits, that glow disappears. I didn't notice this explained in the game and it's easy to miss, but is quite handy to know.

The controls are mostly swipe-based and work fine. You tap once to switch character (Paul or Percy), swipe to make them move, swipe downwards to stomp or upwards to jump. You can push a brown block by walking into it,� providing there's nothing on top of it or blocking its path. Sometimes you need to stomp a block while the other character is standing directly opposite, to hoist them higher, so they can jump onto an otherwise out-of-reach platform.

You can try Paul & Percy on your computer, as a free online version is available, but it really feels much better on an iPad. This game delivers decent puzzle-solving entertainment, with 50 levels and 15 local in-app achievements. The levels require some brain-activity to solve, especially if you're shooting for gold medals and all the biscuits, so it's really satisfying when you beat a level for a gold medal. I'm not certain who stole the biscuits yet, but since one character is shown alongside the associated achievement, I've got a hunch who it might be!

Tower defense games are a dime a dozen these days and Wild Defense [99�/$1.99], in spite of its zesty-fresh tropical flavor, doesn't bring anything really new to the table. Still, that doesn't stop it being a moderately entertaining affair. Less a game for the casual enthusiast and more for the hardcore fan, this one is for those who just have to have another tower defense game on their phones.

Functionality-wise, Wild Defense will be rather cut and dry for tower defense aficionados. Your objective is a simple one: protect your fortress from the enemy waves. To accomplish this, you'll have to drag and drop your units onto strategic locations in the map, all the while trying to maintain a proper composition of troops to ensure that you can deal with the various enemy types. In addition, you'll also have to do things like purchase weapons for your army, work with bombs, cast spells, defeat bosses and occasionally play the Wild Defense equivalent of Russian Roulette.

I'm especially fond of the last, by the way. Though still essentially the same tower defense game, there's also a random element of luck: you'll only be able to use whatever the RNG has selected for you be it a tamer (she's a rather scantily dressed chick with a whip, one capable of lowering defenses with every blow she renders) or extra currency. It's a small twist but it provides a refreshing touch.

That said, Wild Defense isn't quite the sure-fire formulaic success that it should have been. Though it has a lot going for it, Wild Defense is also plagued with small flaws: the jagged difficulty curve, the pause button that sends you to a menu instead of halting the action so you can adequately plan your next move, and bare bones plot (a crying shame given that the setting is all kinds of awesome) are but some of them.

All these would have been forgivable, however, if it wasn't for the fact the interface is painfully clumsy. In theory, the whole drag and drop thing should have worked fine. In practice, it's a lot less effective. For one, it's impossible to tell the range of a unit prior to setting it down and by then, it's a little too late. This, in turn, wouldn't be so bad if things could be sold for a decent value. You can see how it all adds up.

Don't get me wrong. Wild Defense isn't bad, per say. The flaws I've mentioned? You could probably fix them with a patch. If anything, Wild Defense is actually pretty decent. Nonetheless, those who are looking to dip their toes into the genre should probably try their luck with another title.