It basically broadsides all the major player personality types as well as being a textbook case for psychological flow. For those who want to create, it offers

It basically broadsides all the major player personality types as well as being a textbook case for psychological flow. For those who want to create, it offers virtually uninhibited creation. The world is a box of lego for you to play with. For those who want to explore, it offers infinite exploration, but there is no pressure to explore if you don't want to. For those who want to socialize, it offers multiplayer (and pets as allies), or you can enjoy the solitude. For those who want to kill or fight there are monsters, and for those who don't there is an option to switch them off. For those who want to collect, there are rare minerals. If you don't want to collect or build or grind, cheats are accepted by the creators and the community as a valid way to play. In terms of flow, the day-night cycle changes the play context often. In standard play it offers a sense of pressure (for those who want it), while ensuring that the player never becomes too overwhelmed for too long, or becomes bored by a lack of action. The desirability of items that you can craft in the game is usually proportional to their usefulness, but also requires proportionally more effort to obtain. Crucially, most of the tools and items are non-essential or it's easy to craft basic versions that will make do. The free-form nature of the game and lack of extrinsic rewards makes it perfect for self-directed goals, which are essential for flow. Its blocky art style is based on programmer art and technical limitations but has a functional purpose and carries a certain style. It's stylistic, not so cartoony as to put off adults, but so unrealistic that the zombies, spiders and skeletons are not scary enough to put off children (or the even the arachnophobic). In terms of accessibility or usability it's awful. Crafting is virtually impossible without the wiki open, for example. Not even the basic mechanics are explained. There's no in-game help. There must be a significant number of people who have played the game only once because of that. Still, if you manage to persevere for an hour or so, you'll have a solid grasp of the concepts of the game. The difficulty is mostly self-directed, as per flow theory. My question is, was all this deliberate? Does Notch have an calculating eye for game design, is it instinctual, or did he manage to hit on an excellent formula by chance? Can he repeat it?