We see all kinds of apps here on Pocket-lint and sometimes there are real gems among the pack. Sparkle 2 - as its title almost seems confidently to declare - really does shine. It's an action puzzle game that requires quick wits and it's kept us engaged for many, many hours from start to finish throughout its Story mode.Sparkle 2\nFormat\niOS | Android | Windows Phone 8\nPrice\n\u00a31.99 | \u00a32.39 | \u00a33.99 (respectively)\nA whole lot of apps depend on matching up multiple coloured objects. Sparkle 2 is no different in this - that is its core gameplay mechanic. But the team behind the game has wrapped that up into a gorgeous looking package that's very easy on the eye. Smooth motion, thoughtfully rendered objects (c'mon, just look at the grass in the image below), special effects that positively glow and audio - including a quality soundtrack by Jonathan Geer and some sinister voice narration - that makes Sparkle 2 truly stand out. Great production values.But good looks mean little without gameplay, and Sparkle 2 gets it spot on here too. A map with multiple pathways opens up individual single-screen levels where many-coloured orbs are pushed in along pre-set paths. As the player you take control of a sling-shot-like platform where you need to launch orbs and match up three or more to clear them away. If inaccurate or too slow the orbs reach the end of the path, dip into an underground hole and the level is brought down in a sea of black.Speed of movement, volume of orbs and number of orb colours all increase as the levels advance, with as many as four separate paths appearing in levels later down the line. It can get pretty tough so you'll need to keep a sharp eye on where orbs are, which colour you have next in line to fire and which ones are best ditched off screen. Add too many mismatches to an orb chain and it extends - sometimes so much so that, again, it's down the hole and game over.To ease the pressure there is a series of power-ups available throughout the game, awarded for combinations and matching large numbers of orbs. They float around and need to be shot down in order to be acquired. Power-ups range from various explosive weapons, others which "paint" orbs as a single colour, some which spin fire from the rune plate that your sling-shot resides upon, or particularly useful ones such as "backwards" which - you guessed it - sends orbs rolling backwards to the start line. There are plenty more besides, but you'll need to play through the game to get them all.In addition there are permanent power-ups that are always in play. It could be the ability to see more forthcoming orbs so you know which you have ready to fire next, the inclusion of a special power-up after every tenth orb fired, or other similar features. Towards the end of the game there are four available slots which can be awarded with such power-ups or left blank to make things even harder - the choice is yours.Throughout 92 levels - we're crossing our fingers that there'll be more in the future as we smashed through them all during several long flights - the difficulty varies. Once you're done and dusted with the map and have acquired all the special keys there are Survival and Challenge modes available to keep you tapping away.And tap away you will with no restrictions. No in-app purchase nonsense, Sparkle 2's cover price is well worth every penny for the uninterrupted and high-quality play it offers. Undoubtedly one of the best, most-polished apps we've seen for a long time.