Boom! - despite its rather innocuous name - is a platformer-cum-racer game that's provided us with some of the best app gaming fun we've had in recent months. Or even years. There's almost an element of Sonic The Hedgehog in this side-scrolling loop-da-loop racer which throws in a mixture of goals per level that vary from easy to taxing to keep you playing on and on.In typical app style levels are short, which makes it an ideal game to dip into when you've got a spare five minutes. But the thing is you won't play for just five minutes. Boom! has kept us entertained over a weekend and beyond with many hours of play time.Boom!\nFormat\niOS\nPrice\n\u00a3Free | \u00a31.99 (all levels)\nWhere\niTunes\nThe storyline goes something like this: Boom! - that's our hero, the green blob that, colour aside, is somewhat reminiscent of one of the Despicable Me minions - needs to save his friend Pinky - the pink blob - from an evil wizard called Belzaar. Sounds like a kids' story to some degree, but whether you care much for the story or not has zero impact on the gameplay.Each level sees Pinky left dangling in a cage somewhere. It's up to Boom! - exclamation mark an' all - to get into his mono-wheel and scout out the location of his friend. A single strike to the cage or its chain and that sees the level complete.Within each level there are platforms, ramps, loops, gold coins to collect and various obstacles that will slow you down or stop you dead in your tracks. Each of these is often used as a device to make up one of the three of four goals per level. For example: "Collect all coins within 20-seconds" might be one goal, while "collect no coins" could be another.Time is of the essence too, but not in a countdown way. Most goals revolve around getting a level completed as quickly as possible - sometimes so fast it's to the point that you'll wonder how it can be done. Such repeat play to achieve various goals rides that line somewhere between frustration and fun - but that's just the ticket; the mix of ingredients which makeuhttps:\/\/www.pocket-lint.com\/assets\/images\/120966-apps-news-hands-on-app-of-the-day-boom-review-iphone-image2-rR0tuFy2bv.pngp an addictive game.\u00a0It's not all hectic button bashing to get to the finish fastest though. The platform genre element comes into play when measured controls become integral to achieving particular goals. There might be a small gap to drop through that requires a deft touch, or an apparent reverse of direction required to find that one final gold coin.The more goals you achieve and the more gold coins you collect the more the game opens up. Extra levels and various objects from the store become available as you advance through the game until, that is, you hit the invisible wall. As with many free-to-download apps, Boom! offers up two world's worth of levels and then it's either 69p per world thereafter or \u00a31.99 for all levels, including yet-to-be-released future levels. It's totally worth it: pay out that \u00a31.99 and you won't regret it.There is a store where coins can be spent, which includes that typical buy extra coins for real cash option, but these can only be used to buy into designer wardrobe gear: different suits for Boom! to wear or jazzed-up mono-wheels. Fun, but never worth paying for.Play isn't just limited to single player. Boom! has been clever by opening up friends lists where you can play time-trial levels head-to-head against other players, alongside international tournaments which will really test your skills. The levels are the same as in the single player, but it's all about being the quickest of the bunch to win. Competitors show up as faded-out ghost runners so you know exactly where you stand in each race.\n\nThere are three worlds packed full of levels for the time being with more promised in the future. Boom! has all the makings of a classic - it's fun, addictive and tricky to master as the levels advance. Top title. Download it now.