November 2011 update: I eventually bought an Xbox 360 and the XBLA Perfect Dark a few months after first publishing this post. The game turned out to be superb; it was wonderful being able to play it at a decent framerate. Unfortunately analogue movement didn’t really suit time attacking the game: judging the narrow stick angle required to speed-strafe was much less consistent than simply pressing [C-Up]+[C-left] on the N64! I always intended to thoroughly update this post, using my own copy of the game to go into more detail confirming or debunking each claimed alteration, but unfortunately I never got round to doing it.
The Xbox Live Arcade version of Perfect Dark was released a few days ago. I thought someone ought to try and compile a list of everything that’s changed from the original. I decided I might as well do it myself!
Unfortunately, this process is complicated by the fact that, er, I don’t actually have the new XBLA game. (Or an Xbox 360, for that matter… is it sad that this new version of a ten year old game is one of the main reasons I want one?) So I’m basing this list on second-hand information: things discussed in forum threads on Rllmukforum, on the GE/PD speedrunning community at the-elite.net (in both this thread and this thread), and on GameFAQs (I asked numerous questions in this thread I started). Also, the Youtube channel of the Elite’s Takahiro Arai contains a complete set of slow, methodical Perfect Agent walkthroughs of every level in the XBLA version.
Please let me know if I’ve missed anything or there’s anything in this list that’s incorrect and I’ll change it.