A bunch of us here at Kotaku are deep in thrall to Threes, a simple-on-the-surface-but-hypnotically deep numerical puzzle game that hit iOS devices last week. (Seriously, look at that picture. We're not even talking to each other.) There was talk of doing our own guide to playing Asher Vollmer's hit game but it came to light that an excellent set of hints already exists. If you're playing Threes,