I’m going to keep this short, because not only is the game itself pretty short, but it’s something you have to experience and play yourself, rather than read what I have to say about it.
The Beginner’s Guide involves a walk through a number games written by the (presumably made up) Coda. The narrator tells you about them, Coda’s likely state of mind at the time, and various other facts about the simple games as you progress through them. There aren’t really any puzzles, there’s very little shooting, and each “game” is very short and mostly simple.
But, as usual in games of this type, that’s not the whole story. The narrator has more than just a history lesson to talk about.
I enjoyed it, although not as much as either The Stanley Parable or Dr Langstrom, with both of which The Beginner’s Guide shares DNA, but it’s worth the 90 minutes or so I spent on it. It’s just a shame it crashes so much on the Mac!