Game development is all about making tweaks. A change here, an improvement there, and pretty soon a bare-bones idea is transformed into a stunning game. Thus, having already built a solid foundation with vertical platformer Mega Jump, you'd hope that Get Set Games could perfect is monster-centric take on the genre with the sequel.

Mega Jump 2's tilt-based action is as responsive as ever, with you directing tiny hero Redford back-and-forth across the screen with subtle hand movements. Collecting items propels the little monster ever higher, while platforms offer a brief respite from the vertical climb. Smash into an enemy, however, and Redford will come crashing back to the earth.

There are a host of power-ups to collect as you soar skyward. One turns Redford into a fireball. while another acts as a magnet for attracting more items. These effects last for only a brief period, but are vital if you want to improve on your high score.

So far, so familiar. However, the simple formula of Mega Jump has been diluted by new complexities. Some items, which are almost indistinguishable from actual collectibles, will run from the ascending monster, ruining your well-laid plans for high score glory. Enemies will also appear with almost no warning, and all too frequently you will find yourself cut off by nasties and unable to proceed.

The problem is that none of the additions seem to have been added to make the game more enjoyable or legitimately challenging. Instead, these difficulties seem to have been added to drive you towards the in-app purchases.

While gems and coins can be earned slowly through play, if you want to get power-ups and new characters before your hair turns grey, you'll have to cough up some real cash. Buying characters and perks will help you to improve your score, but the option to drop coin to get them quicker renders the leaderboards next to useless.

Though still as entertaining a premise as it ever was, Mega Jump 2 struggles to live up to the original. By adding questionable new mechanics and free-to-play hooks, the dev has watered down the game's concentrated core to something slightly more bland and, ultimately, forgettable.