I’ve known about Rob Hale pretty much since he posted his first weekend game videos on YouTube (a game that would later turn into the popular Waves). But I only recently stumbled upon his old game design blog. There’s a wealth of information here, but three posts in particular I found extremely informative and thought-provoking. Hopefully you will feel the same.
Failure and Learning: How to incorporate “punishing” the player into your game. Punishment is generally regarded as a bad thing since it gives players a reason to stop playing, usually because of frustration. But failure can also be a good thing.
7 Ways to Make Your AI Smarter: No real code or process discussed here, but this article does raise several other avenues of AI development that many people (including me) often neglect.
Continuity Level Design: A ridiculously good post filled with lots of images and examples. Also one of the most in-depth analyses of level “flow” that I have ever seen. If you’re a level designer, definitely look into this for ways to improve your work.