Another great example is "A Dark Room" - a game in which the mechanics are introduced one by one in such a smooth way that no tutorial is ever needed. edit to

Another great example is "A Dark Room" - a game in which the mechanics are introduced one by one in such a smooth way that no tutorial is ever needed. edit to add a link: http://adarkroom.doublespeakgames.com http://adarkroom.doublespeakgames.com it's a very simple free game that (last I checked) can be completed in an hour or two.