Crayon Physics Deluxe

A box melting from the heat of the sun on a summer afternoon, a handful chucked at a sibling – this is the extent to which the world has known crayon physics until today. Crayon Physics Deluxe draws new territory beyond allowing adults a reason to play with crayons, but in its unique physics-based gameplay.

The objective is simple: guide a red ball to a yellow star. It's the way in which you get it there that's the crux of play. You have no direct control over the ball and are only capable of giving it a gentle push. Each level has a unique assortment of line drawings making up a basic landscape for you to fathom a way across. In many cases it's the yawning gaps between the hand-drawn protrusions that pose the greatest challenges.

Most titles use graphics to enhance gameplay, but here they're an integral part of the physics engine that gives the game its name. The touchscreen beautifully hosts the delicate, coloured lines that lend the game such wonderful style and the folded, faded paper background adds ambiance to the crudely-drawn levels. Neither does the reduced screen size have any real impact on the accessibility or visibility of those simple doodles, so the vital graphical element at the core of Crayon Physics Deluxe has been fully retained.

Good thing too, because the only tool at your disposal is a steady finger. Drawing on the screen creates a thin crayon line, which can be used to create any shape required to get your ball to its destination. Once drawn, the line (or shape, if you've rendered a crude circle or square) solidifies and becomes subject to the same weight, inertia, and gravity controlling the ball.

To cross a gap, for instance, you might draw a straight line between two blocks and then push the ball across. You might also draw a large shape around a pivot point and use it to counterbalance an obstacle – lifting or pushing it out of the way so the ball can get through. Since you can also draw pivot points to hinge two shapes (or attach one drawing to another) and flexible pieces of string, there's practically no limit to the rudimentary mechanical systems you can create to solve these physical enigmas.

While some of the levels are quite perplexing, turning into awe-inspiring structures when solved appropriately, others aren't quite so challenging. At times you'll be utterly engrossed in the virtual machinery you're constructing to get the ball home, getting a sense of satisfaction from your own clever wax-based engineering skills. Other times, however, you'll feel as though you found a way around the problem by blind luck or a method the developer never intended.

Swinging a crayon-drawn club that happens to fall off its pivot point might still knock the ball into the star, despite the fact that you haven't solved anything or used the apparently necessary scenery to fathom the correct method. This isn't a particularly satisfying experience. In all likelihood, the game wasn't designed with any real method to its madness and solving the puzzles by any means is what the designer intended. Nonetheless, there's still a nagging disappointment when it's possible to circumvent rather than overcome a challenge.

But the sheer novelty value of seeing crayon doodles jump into existence on the page and roll, pull, knock over and build physical objects is quite priceless, so it's easy enough to forgive the less rewarding levels.