5th Cell's latest has the same generosity of spirit as its most famous creation, and a similar way with misleading numbers. 420 levels sounds a lot for an iOS platformer, but, as with Scribblenauts' 20,000 nouns, the differences between one and the next aren't necessarily as meaningful as you might hope.
Those stages are short, too, with most taking five seconds to complete, and a good portion under three. With its micro-levels conquered by a single command – all Roo has to do is jump – it's so reductive it could almost be a satire on smartphone gaming itself, the perfect platformer for Generation ADHD.
A wonderfully efficient setup provides the motivation, six comic panels on a single screen setting you on a journey across Australia to reach Sydney Zoo and Roo's kidnapped joey. The trip comprises 20 chapters, each introducing a new mechanic, from swings, springs and oil slicks to propellers, umbrellas and cannons. Arrows showing the timing of your taps remain after a failed run; this should make corrective action easier, but the allure of a gold star for beating the par time will have you hitting the reset button rather than continuing – not least because even the toughest basic stage shouldn't take more than a handful of attempts to beat. Similarly, the throb of the stopwatch as it nears the upper threshold for a gold-rated time should add a minor note of tension as you cross the finish line, but by that stage there's often no way to affect the outcome.
Complete the 15 basic stages on a chapter and you'll unlock six 'extreme' variations, at which point the overly gentle difficulty curve steepens dramatically. After what amounts to 20 consecutive tutorials, cramming five stages' worth of hazards into one is the worst possible way to increase the challenge, rewarding bloody-minded persistence over mastery. On completion of these ludicrously exacting reflex tests you feel relief rather than satisfaction; only the most masochistic of players will revisit them. And would it be unkind to suggest a link between the artificially high difficulty level and the presence of in-app purchases to skip stages entirely or play them in slow-motion?
It's becoming a 5th Cell tradition: strong ideas compromised by erratic level design and structural weaknesses. One day, the developer will find the right balance to support its undeniable creativity, but sadly, it hasn't found it here.