I just remembered this amazing piece of writing the other day about Infinity Blade (which was a lot of fun actually). It's definitely one of the most clever articles on a game I've ever read. The Grimrock article on RPS today reminded me of it because of how it integrated game dynamics into the review itself. I'm not sure if it will make as much sense if you haven't played it but it should become pretty clear once it gets started.
More conventional articles now. Two superb articles on game and level design in Super Metroid:
Anyone else have any hidden gems they would recommend?
(As an aside, if you haven't read RPS Blood-bowl or Solium Infernum diaries then you are really missing out.)