Here's my first attempt at a game development video tutorial. My plan was to record all of the steps that go into creating a simple game (for writing the code, at least). It's probably too boring to be that useful and it doesn't cover much in 15 minutes. I also sound very nasal, which could be because I was using the microphone that's built into my laptop.
I planned to add a little introduction to the beginning of the video, but it ended up being exactly 15 minutes so I didn't have room. Also, I think it's neat that it turned out to be exactly 15 minutes so I wanted to leave it alone (like when the gas pump clicks off at an even dollar amount).
The game I'm working on for the tutorial is an action/platform/racing game. The goal isn't just to complete a level, but to complete it as quickly as possible. This makes it a little more casual because it's more forgiving - when you screw up you don't die and start over, you just have to try again from where you are. It also makes an "implied" multiplayer mode because you're competing against everyone else on the high score table.
I have a feeling this would work better as a written article with embedded videos. The article would show a chunk of code, then have a 10-30 second video of what you'd see when you run the game given all the code that's been explained so far.
Based on how this video went, I'd estimate that the next 15 minute segment would cover adding powerups, variable-height jumps, and a HUD-based clock. The 15 minute segment after that would cover adding two kinds of enemies and map creation.
It'd cover a decent amount of stuff. It's quick when you think about how long it takes to make a game, but 45 minutes is still a long video.