The aforelinked guide to Threes strategy was via this stellar review of Threes by John Teti (this one’s via DF):
Here I’ve made two sixes, and I’m about to slide them together for a 12. The sixes gaze into each other’s eyes in anticipation of their mathematical destiny. This is one of the earliest glimmers of personality in the numerical cast of Threes. Later, the tiles will grumble, sigh, and playfully heckle you as you consider the board. The bigger numbers have bolder, more fully formed personas than the little ones. The tutorial is charming because it holds the promise of more whimsy; the game is charming because it delivers on that promise.