For something like that, do those people work full time on just that one game? Or are they also working on NFL/NBA 2k2 at the same time, creating UI code that works across all the games in the series?

We were not a typical sports game studio (Treyarch), and the other sport project that was done at the same time was for EA (some baseball game), while the one I was and talking about was for SEGA. It was a bit of a problem really, so people were not allowed to get mixed into teams. After that game Treyarch moved to do mainly Spiderman, and then Call of Duty. The latest COD also has quite a spectacular UI system, but much less coders are involved into bringing it up. But today's standards are even much higher - cool animations, links, socially enabled (twitch, facebook, etc.).

Some studio have made success with flash-compatible renderers, and we even thought for NHL2K2 to use one, but first it was only compatible with the Windows version of the Dreamcast (okay, I barely remember now, as we didn't used it, but there was a choice whether you can ship your game with some barebones NT system on the Dreamcast - but you had to lose 2mb to the oS). So that middleware (I think) required it, and it wanted somewhere from 2-4mb more on top.

One big problem, back in the days, with the UI is that you can have tons of memory in your main menu, but you barely have anything while the game is playing. So your "PAUSE" menu might use completely different code path, and look quite differently. The alternative is to reload things after PAUSE, but this decreases the quality of the product, also much harder to test, and you would hear the DISC "screaming" soo much :)

Nonetheless Dreamcast was fun to work on, spare the compiler, and the debugger :)