For our money, when it comes to gaming ideas, the simple ones are the best ones. Just look at what the team behind Polara managed to achieve with just a simple color-switching mechanic, gradually teased out into a wonderfully complex arrangement of twists, traps and cunning design.
The core gameplay of Flow Free is similarly simple on the surface, and each one of this free game's hundreds of levels boils down to two key challenges: join a selection of colored dots together with finger-streaks, and make sure that the lines you leave behind, when combined and without overlapping, cover every last square on the grid.
It starts off simply enough, with 5 x 5 grids being very easy to cover. You'll have no trouble connecting the dots and covering the grid completely, joining nearby dots directly with each other and taking the long route around the grid for those dots that are placed further apart. From here, the number of colors you need to bring together increases, and the size of the grid you need to cover gets even larger.
It's only really in the later levels that the challenge at hand ramps up seriously though, and we'd like to have seen that jump in difficulty be a little less spiky. Once you're deep into Flow Free's 9x9 boards, the lines you need to draw have to take an exceptionally wayward route towards their end-point, and the adjustment to the level of strategy involved is jarring.
The action goes all the way up to 14x14 for those of a steely disposition, and there are additional level packs to be purchased from the in-app store if you're still hungry for more. Alternatively, you can head into the Time Trial mode to see how many puzzles you can solve within a fixed amount of time.
Taking everything into consideration, you can't see Flow Free as anything other than a fantastic puzzle package. It's a simple but compelling concept, the game is completely free, it's supported by very unobtrusive adverts, and there's a generous quantity of puzzles to get stuck into. It's unquestionably a game that deserves a home in any puzzle fiend's collection.
What's Hot: A fantastically simple puzzle idea that heads towards unexpected depths.
What's Not: That leap in difficulty is just a little bit too much.