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!