It was my favorite game in school and, at some point, i swear, I remembered all maps from the beginning until, at least, to chapter "surface tension". But twelve years later I have found, that although I still remember chapters order, but have completely forgot all small details and the entire feeling from game is slightly shifted from regular first person shooter to brilliant sci-fi story action game.
And 20 years old graphic technology is not breaking experience of watching slightly scary movie about brave scientist.
Enterance to final boss is magnificent