Telltale and Micrsoft have made the first episode of Minecraft: Story Mode available for free, providing that a) you have Windows 10, and b) you download it from Microsoft's store. This comes a month or so after the release of the final (for real) part of Telltale's episodic Minecraft adventure, which was originally going to be in five parts, but eventually ballooned to eight, with the addition of three bonus chapters.

All of which means there's a 'complete' version of Minecraft: Story Mode available that is not complete, and a 'complete' version that is. So be wary if you intend to buy the whole thing.