I am personally a huge fan of Minecraft. Throughout the years I have constantly been inspired by the ability to explore and create thorough out the environment in a way that is constantly changing and morphing with every seed, and even more so when the environment is shaped by what I and my friends create.
The core mechanics that allow players to engage with the world include the movement keys which give range of motion in the xyz axes, the camera view control through the use of the mouse, and finally the destroy and interact (most frequently by building) mechanics. These allow players to control their avatar and experience in a way that is quite similar to vision and movement in the real world, which for me, allows me to experience the world and enjoy the fun of discovery and self expression through exploring and building in this world. By making the experience similar to that of vision and moment in real life it is very easy to pick up this method of exploring the generated world.