Absolutely 100% an amazing game. Obviously it's not a carbon copy of Doom, but i love the risky approach they took with fear based more on atmosphere and being helpless, rather than a barrage of enemies, and the graphics still hold up 18 years later.
My only complaint, and the only reason i didn't give it 5 stars, is that for some reason the jukeboxes in the game refuse to let me play 2 hours worth of Nickelback's hit song "Rockstar", and i just can't play games without it anymore. Amazing, nonetheless!