Puzzle games come in all shapes and sizes, which is good. Distinction and variety is important in a genre that's meant to test your brain power. That said, the simplest puzzle games are usually the most memorable ones. Tetris, for example, is ridiculously easy to learn and play, but its staying power across the decades can't be denied. Similarly, Bicolor by 1Button is quite easy to learn and play, which lets players dive into round after addictive round. While Bicolor doesn't vault over the bar set by Tetris in the long-ago and far-away, it's still a clever and challenging diversion.
The mechanics of Bicolor are a bit difficult to explain, but they're easy to understand once players get their fingers on the game and work through the tutorial. Each two-color stage presents the player with a tangle of numbers. The numbers indicate how many spaces a square can be dragged around for. Then the opposite color must "eat up" the lines within a certain number of moves, and without leaving anything behind. The bi-color lines must be connected in order for them to erase each other; lines can't cross gaps. When the screen has been cleared of lines and numbers, players are allowed to move on to the next stage.
Bicolor introduces itself with a gentle hand. In fact, it starts off deceptively easy. Players may even slide effortlessly through early levels and start getting big ideas about how smart they are. But shore up that confidence: by the time the second set of levels is unlocked, the numbers get bigger, the paths get trickier to draw, and egos get pelted.
Bicolor is built on an original concept, it's easy to learn how to play, and its challenge level steadily creeps upwards in a way that ensnares players before they even know they're caught. Take heed, puzzle fanatics: this one is well worth its (reasonable) asking price.