Grey. For sure.
Killing off the main characters is horribly clichéd, what would be far more interesting is to see the Combine threat subverted at a huge moral cost. Essentially an ending where the combine are finally defeated, but only by signing up to what may indeed be an even greater...
Never scary, but definitely creepy and disturbing. It presents a very believable dystopian future (aliens aside!!), and the bleak locations and music help.
I am always disappointed by the post 99 releases of UT - probably because I was so enthralled and addicted to the original game back in the day.
The newer games are just nowhere near as fun, it's sounds crazy, but I genuinely think Epic have "consolified" the franchise. There was something...