I promised I would talk about how well designed Team Fortress 2 is, but I didn't get around to it until now because I kept playing the game instead. I was pleasantly surprised when I started playing the game; it seemed like every problem I ever had in a multiplayer FPS was absent. I'm only going to talk about one problem TF2 solved though: getting lost.
I played a lot of Enemy Territory before TF2 came along. It was the first multiplayer FPS that I was really into. I remember when I first started out. I would pick the engineer because, you know, I was studying engineering, and I would start out with a bunch of other players, and there I was on a completely new map with some complicated objectives to complete, and I was always like, "where do I go? What do I do? I'm LOST." And of course I would start asking people, and if someone had done that map before, they could tell me, but it still took a few more plays and a couple hours of looking like a noob (ET matches go up to 30 minutes) to figure things out.
Right? Left? Forward? I have no idea.
As much as I like mazes and hide-and-go-seek, this experience of being lost for hours is never, ever fun. I play games like these to kill people, capture the flag, and then brag about how awesome I am. I don't play to wander around. So I was very happy to find that TF2 maps were designed to make it clearly obvious where you are supposed to go next. TF2 has these big, outrageous, ridiculous signs that point where to go. If you are on the blue team, you've got big blue ones to follow. The red team has red signs. Plus, in each base, there are explicit signs that tell where the intel (flag) is, and where the exit is. From the moment you start playing, you can actually get straight to the killing and the stealing and the smack talking without much trouble at all, and when you happen to actually steal the enemy intel and you are suddenly realizing that YOU HAVE TO GET OUT OF THE ENEMY'S BASE RIGHT AWAY BECAUSE YOUR COVER IS GONE AND THEY ARE ALL COMING FOR YOU, you can immediately figure out which way to go so you actually stand a chance at winning and you won't get stuck in a corner and pwnt.
See? Big fat sign.
So let's look at it this way: the game is the user interface and the goal is to have fun. TF2 is designed to make reaching the goal as easy as possible. Why can't all interfaces be like that? I have a new lesson plan for any UI design students: 15 hours of TF2, one credit, letter grade only. Further independent study is also an option.