I finally have a serious complaint about the Portal games - commentary mode is kind of a pain in the ass. There are basically two problems with it. 1)The game doesn't give you accurate information about how many commentary boxes are left to find (they are numbered, but the numbering scheme is per area, not per chapter, and not every area has them - something I did not figure out until doing the last chapter of Portal's commentary). 2)You cannot save in commentary mode, which means that you have to do an entire chapter in one go.
Nonetheless, I learned some interesting things from the commentary. Like the fact that when you place portals opposite each other, there are a maximum of 9 reflections, or that Wheatley was originally slated to be six different spheres.
But I suppose the biggest thing I learned was a theme that kept getting repeated - that the reason the games so often feel like a psychological experiment is that it is the result of a process of psychologically experimenting on the playtesters. Frequently, puzzles were made easier or more difficult by subtly changing the layout or set-dressing of a chamber. It's really interesting to see how my perception of reality is influenced by factors I'm not even consciously aware of.
The other interesting thing I learned was that the portals played havoc with basic physics simulation. This surprised me, mostly because I hadn't thought about it, but if I had thought about it, I would've thought that transporting something through a portal would have simply been a matter of deleting it in one location and loading it in another, but apparently, the physics have to work through the portals and it required some clever programming to make it happen.
That seems strange to me, that creating a simulated teleportation device can cause the simulated laws of physics to break down, much the same as a real portal device would break the real laws of physics. Then again, I could be misunderstanding the basic nature of the problem.
Glimpsing behind the scenes of Portal just deepened my respect for the games, and despite basically just repeating them a second time, I didn't really get bored with them at all. Which is interesting, because they are as linear as it's possible to be. It goes against my normal gaming instincts - I usually prefer games that are open-ended, or have a lot of choices, or at the very least have enough side-activities that I don't have to do everything in the same order.
I suppose I shouldn't be surprised. There are books I've read a half-dozen times, and they've never changed. There are some movies that get better when you know how they end. There's no reason a video game can't simply tell a good story without also being a fully-realized virtual world.
Anyway, in case it's not obvious - I highly recommend these games.