In superhuman, a favourite toy is the time auto completer which you use to snooze emales. Do they indulge playful exploration? Are they fun even without a goal? And do they create moments of pleasant surprise? If so, then congratulations, because you're on the way to building a great game. The previous four factors are critical to game design, but perhaps the least understood is flow. Flow is an intense and focused concentration on the present. It is so absorbing that we don't about the future or worry about the past. We must always know what to do next. Number three, we must be free from distractions. Number four, we must get clear and immediate feed back