They say that if there were a nuclear holocaust, the only thing left would be cockroaches. I think there's probably something else that would survive along with those creepy crawlies, one thing that slowly seems to be taking over our daily lives: colour-matching block puzzles.

Shifters is one of the genre's newborn and it comes with a slightly softer side than some of its more hardcore brethren. This is a game that wants you to learn, setting fairly simple challenges one after the other until you get the gist of play. Naturally, most of the tasks revolve around matching coloured blocks - in this case, lines of three or more, either horizontally or vertically.

Playing in an 8x8 grid, you control a cursor that rotates four squares at a time (either clockwise or anti-clockwise, switched via a tap of the '0' key). The idea is to manipulate the grid so that squares of matching colour are lined up and cleared from the board altogether, naturally replaced by further blocks falling from the top.

If your goal isn't to reach a set score limit, then you'll find yourself attempting one of three other games: trying to remove blocks of just one particular colour, clearing groups of four or more, or twisting the blocks so that they match a set pattern within a time limit - a face, or body set in a particular pose, for instance.

Though the initial rounds feel a little like baby steps (and it's perfectly possible that, at this point, many seasoned puzzle gamers might well feel too frustrated with the slow pace to see it through), they do an admirable job of keeping the game's goals in check - so much so that there's little call for any kind of tutorial or extensive help files, though the latter is available.

This, essentially, makes Shifters the perfect starting point for gamers who've never touched a colour-matching puzzler in their lives, though there are a few other elements that add a level of complication to play for those who wish to indulge them.

For instance, in the game's main colour-matching mode, you'll find bombs and sticks of dynamite beginning to populate the board if you clear four or five blocks at a time, respectively. These items then 'blow up' your score somewhat when activated, clearing the area around them of blocks and topping up your total no end.

This adds a slightly more strategic element to play for those who wish to buy into it, allowing players with the skill at their fingertips to plan ahead and activate bomb after bomb, dynamite stick after dynamite stick.

Indeed, such talent becomes a necessity as the levels pass, with Shifters adding a time limit and upping your targets as you reach the more testing stages. Some of the most difficult are those that only count blocks cleared in gangs of four or more, as moving the blocks around to get four in a row without inadvertently clearing a line of three instead is far from easy.

But, considering Shifters's progress is so slow and steady, there's a fair chance that most gamers will be fully schooled in the ways of block manipulation by this stage, having come through the early stages with a barely a trace of sweat upon their brows.

Shifters feels specifically designed to build confidence, upping your skill set as you go so you can tackle the game's more ferocious finales.

All that said, even when playing its hardest hand, Shifters is never the most taxing of prospects, but it's the kind of game that fills a hole, raises a smile and gets you ready for its tougher counterparts.