I looked around the documentation, and I can't find out if it's a good port or not. >.> Is it missing anything?
No, this is an excellent port. There was a TC a few years back, made by the same guy and a few other people, that was missing quite a bit (most notably the awesome lighting, seriously, this game had the best static lighting ever), but not this. This is based on data ripped from the Doom64 ROM, and the engine was reverse engineered. It should be very true to the original, with the exception of a few bugfixes. The only problem I've had with this is an issue with quicksaves occasionally crashing the game. I sent a save to Kaiser and he got back to me with a new .exe to test, which I'll do this afternoon.
From that thread, this massive image gives you an idea of how poor the lighting was in the TC. I don't want to say "poorly done" because it was the best they could do with the existing sourceports:
http://img395.imageshack.us/img395/7008/doom64portcompareug1.jpgI've never played Doom 64 before, but it looks like a decent port. I got stuck in level 2, can't seem to get the blue keycard...
Once you "release" the keycard, go along the one wall, where there are four alcoves. The three with computer terminals in them are crushers, the other one will lower one of the boxes that the keycard pops out of. Run into that alcove, then run back to the box and grab the keycard.
We have EVEN MORE themes now, but some old ones are gone...