APP OF THE WEEK:iPad (also iPhone, iPod Touch) Chillingo *****

A curious hybrid of Apocalypto and gardening, Totem Runner is an inventive app and a new twist on the side-scrolling platform game. It follows a mysterious silhouette wearing tribal clothes. He’s constantly running from left to right and drops seeds to “free the living world that awaits the execution”. Colourful plants spring to life in his wake.

The game-play here is gloriously simple. As you ramble along through the foliage, you tap the screen to transform into appropriate animals. “Fly with eagle’s wings” to soar over and around obstacles, become a boar (or “rage totem”) to barrel through enemies and turn back into human to plant seeds. Just like the tools in rock, paper, scissors, each form has its strengths and weakness.

It’s an unusual game, and one with an attractive, artful presentation (striking silhouettes over vibrant backgrounds) and relentless, mesmerizing pace. Totem Runner was a recent Editor’s Choice in the iTunes store, and deservedly so. Conservation and gardening has rarely been this vigorous.