Simple, elegant design is the guiding principle behind 1Button's entire catalogue of apps and games. And with Bicolor, the tiny French developper has channelled this philosophy into an inventive puzzler we can't stop playing. Bicolor's accessible charm and beautifully minimalist presentation will seduce you from stage one. But the game's emphasis on logic and experimentation—and the sheer giddiness you'll feel after solving it's most devious conundrums—are what ensure you'll return to it again and again.