It sounds simple enough – just slide the gaps in the on-screen lines to allow red and blue balls through to their matching coloured areas (fire and water) to complete each stage – but puzzler Orph soon increases in complexity and offers an addictive challenge. Multiple balls and lines make your task akin to juggling as you try to keep some balls contained while allowing others through, and you also have to account for balls colliding and changing trajectory. Later levels introduce switchable coloured lines that only allow matching balls through, plus balls that can be tapped to enable them to pass through lines for three seconds. Completing a stage in faster time earns you up to the maximum three-bar ratings, adding an incentive to replay levels. This is probably just as well as there are currently only just over 50 levels.